Research reported in this publication was supported by a generous gift of 14-month-old female CBA mice from the National Institute on Aging, Aged Rodent Colony (Nancy Nadon) and by Utah State University, School of Veterinary Medicine, Department of Animal, Dairy and Veterinary Sciences.

All methods described here were developed under National Research Council guidelines found in the Guide for the Care and Use of Laboratory Animals and have been approved by the Utah State University Institutional Animal Care and Use Committee.
NOTE: Ovarian transplantation procedures may involve mice (CBA/J strain) from 21 days of age to 18 months of age. Mice of the CBA/J strain become reproductively competent between 45 and 60 days of age and reproductively senescent between 10 and 12 months of age.
1. Transplantation of intact ovaries to aged mice
NOTE: This first protocol describes the procedure used during the transfer of ovaries from a young mouse (60 days of age) to a postreproductive female (12 months of age) of the same inbred strain. The same procedure is used for ovarian transplantation between any two female mice.
<ol>
	<li>Weigh and anesthetize the donor animal by intraperitoneal (I.P., 27 ga needle) injection, for example using a cocktail of ketamine, xylazine and acepromazine (65 mg/kg ketamine, 13 mg/kg xylazine 2.0 mg/kg, acepromazine; cocktail dose - 6.5 ml/kg). Return the animal to the heated home cage until the anesthesia has taken effect.</li>
	<li>Once anesthetized, remove the animal from the home cage and place on heated paper towels. Using clippers (#40 blade preferred), remove the hair a few mm lateral to midline on each side, starting just below the ribs and moving distally, preparing a clipped &#39;patch&#39; approximately 2-3 cm square on either side of the prone mouse leaving a strip of hair approximately 1-2 cm covering the midline.</li>
	<li>Lightly wipe the clipped areas with 70% ethanol and, apply betadine solution to the clipped site with a cotton-tipped swab.</li>
	<li>Apply antibiotic gel for eye protection and administer meloxicam (2.0 mg/kg) subcutaneously (S.C., 27 ga needle) on the lateral aspect of the animal&#39;s neck for postoperative pain relief.</li>
	<li>Place the animal in prone position on a heated sterile surgical field, and wipe the clipped area with a 70% ethanol-soaked 2 cm x 2 cm cotton gauze.</li>
	<li>Make a 1.0-1.5 cm paralumbar incision and bluntly dissect the skin from the underlying fascia. Make another incision through the fascia. Bluntly dissect laterally under this fascia as superficially as possible until reaching the abdominal cavity</li>
	<li>Place a small surgical drape over the incision (cut from 2 cm x 2 cm gauze) and wet the drape with sterile saline.</li>
	<li>Using small forceps, locate the adipose tissue that surrounds the ovary in the abdominal cavity and gently extract the fat pad and ovary and place it on the wetted gauze drape. The ovarian fat pad will appear more &#39;white&#39; than the surrounding adipose tissue.</li>
	<li>Place a 1.5 inch Bulldog clamp on the fat pad (taking care not to obstruct the ovarian bursa) to hold the tract in place during the procedure.</li>
	<li>Move the dissecting microscope into place and clearly identify the ovarian bursa. Grasp the bursa with two watchmaker forceps and incise the ovarian bursa opposite the ovarian hilum to expose the ovary. If the intended access area of the bursa is highly vascularized, apply a drop of epinephrine (1:100,000) with a syringe to the bursal surface to reduce bleeding at the time of tearing.</li>
	<li>Gently remove the ovary from the ovarian bursa and excise the ovary by clamping at the ovarian hilum with a watchmaker forceps to prevent bleeding.</li>
	<li>Place the donor ovary in watch glass filled with 4&#176; C sterile saline, loosely cover and set aside until ready for transplantation. Ideally, place the watch glass under an additional dissecting microscope so that the ovaries can be easily grasped by the surgeon at the time of transplantation.</li>
	<li>At this point, either euthanize or set aside the donor mouse&#160;(must be continuously monitored) to receive a transplanted ovary, tissue, cells or a placeholder glass bead at a later time point.</li>
	<li>With a clean surgical field and instruments, ovariectomize the recipient animal as above. Older mice tend to have an increased amount of adipose tissue and may require an increased anesthetic dose (up to 20%).</li>
	<li>After excision of the ovary from the recipient, place a small piece of hemostatic foam pad inside the empty bursa to control bleeding and aid in clotting and place a small piece of saline-soaked gauze over the exposed site.</li>
	<li>Locate a donor ovary (or tissue, cells, placeholder glass bead) with a watchmaker forceps in one hand and move into the microscope field-of-view. With another forceps in the opposite hand, remove the gauze and simultaneously remove the hemostatic foam pad from the bursa while placing the new ovary inside the bursa.</li>
	<li>If the new ovary does not fit inside the recipient bursa, cut the donor ovary in half (or 1/3 or 1/4) and place into the bursa in pieces. If the bursa does not completely cover the entire ovary, place a suture through the bursa, through the ovary and back through the bursa to hold the ovary in place (see Discussion section). 
	NOTE: The glass place-holder beads can be difficult to handle with watchmaker&#39;s forceps.</li>
	<li>When placing a glass bead inside the bursa, pick up the bead with larger forceps and drop on top of the fat pad next to the ovarian bursa. Roll the bead into the bursa.</li>
	<li>Pick up a Castroviejo needle holder already loaded with a tapered needle and 9-0 or 10-0 monofilament suture, locate the torn edge of the bursa and close the bursa using one or two Halsted sutures. 
	NOTE: Suturing can alternatively be performed with watchmaker or other small forceps.</li>
	<li>Irrigate the site lightly with sterile saline, remove the fat-pad clamp and return the ovary/fat pad to the abdomen.</li>
	<li>Remove the drape and close the abdominal wall with 6-0 chromic gut or vicryl. This step can be done with or without the microscope.</li>
	<li>Move the microscope aside (if not moved in the previous step) and close the skin with 9 mm wound clips.</li>
	<li>Place the animal in a heated recovery cage shaded from light and monitor the animal continuously until recovery from anesthesia. Additional meloxicam may be used 24 hours post-operatively if indicated. Remove the wound clips approximately nine days post-operatively. 
	NOTE: No immunosuppressive techniques are employed and no evidence of graft-versus-host disease has been detected post-transplantation or at death.</li>
</ol>
2. Transplantation of germ cell depleted ovaries to intact mice.
NOTE: This protocol involves the transfer of ovaries from a young, germ cell-depleted mouse to a postreproductive female. In this protocol, the ovary recipients and the ovariectomy and transplantation procedures are as above with the exception that the transplanted ovaries have been chemically depleted of primordial and primary follicles/germ cells. Remaining secondary and antral follicles will undergo recruitment/atresia leaving the ovary devoid of germ cells. Germ cell depletion with 4-vinylcyclohexene diepoxide (VCD) is well described16. VCD is a toxin. Because the VCD-treated ovaries are being transplanted to a non-treated mouse, this procedure benefits from a VCD-treated ovary in a mouse not exposed to the toxic effects of VCD. This protocol describes the procedure for germ cell-depletion in young, ovary-donor mice.
<ol>
	<li>Dilute VCD (64 mg/mL) in sesame oil for injection and store at 4&#176; C until use.</li>
	<li>Inject ovary donors once a day with VCD I.P. (160 mg/kg) for 15 days beginning at 28 days of age. Inject control mice with sesame oil following the same schedule.</li>
	<li>At 50 days of age, check VCD-treated and oil-only-treated mice for cessation of reproductive cyclicity for 10 days as above. At 60 days of age, VCD-treated mice should display no cytological evidence of gonadal input.</li>
	<li>Recover ovaries from 60-day-old mice and transplant as above.</li>
	<li>Determine successful transplantation of germ cell-depleted ovaries by detection of a lack of reproductive cycling and increased levels of circulating androstenedione. Androgen:Estrogen ratios increase significantly after germ cell depletion with VCD17.</li>
	<li>Initiate vaginal cytology 10-14 days postoperatively and collect data for at least 10 consecutive days to ensure accurate determination of cyclicity.</li>
</ol>

<ol>
	<li>National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Fertility and Infertility Branch. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term='Fertility+Status+as+a+Marker+of+Overall+Health'.+"Support+studies+that+investigate+fertility+status+as+a+marker+of+overall+health+for+both+men+and+women".">'Fertility Status as a Marker of Overall Health'. "Support studies that investigate fertility status as a marker of overall health for both men and women".</a> New Research Priorities. , (2016).</li><li>Eisenberg, M. L., Li, S. F., Behr, B., Cullen, M. R., Galusha, D., Lamb, D. J., Lipshultz, L. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+estimate+of+the+worldwide+prevalence+and+disability+associated+with+osteoporotic+fractures.">An estimate of the worldwide prevalence and disability associated with osteoporotic fractures.</a> Osteoporos Int. 17 (12), 1726-1733 (2006).</li><li>Rosario, E. R., Chang, L., Head, E. H., Stanczyk, F. Z., Pike, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+levels+of+sex+steroid+hormones+in+men+and+women+during+normal+aging+and+in+Alzheimer's+disease.">Brain levels of sex steroid hormones in men and women during normal aging and in Alzheimer's disease.</a> Neurobiol Aging. 32 (4), 604-613 (2011).</li><li>Cargill, S. L., Medrano, J. F., Anderson, G. 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M., Nazokkarmaher, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manipulation+of+Ovarian+Function+Significantly+Influenced+Trabecular+and+Cortical+Bone+Volume,+Architecture+and+Density+in+Mice+at+Death.">Manipulation of Ovarian Function Significantly Influenced Trabecular and Cortical Bone Volume, Architecture and Density in Mice at Death.</a> Plos One. 10 (12), 15 (2015).</li><li>Peterson, R. L., Parkinson, K. C., Mason, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manipulation+of+Ovarian+Function+Significantly+Influenced+Sarcopenia+in+Postreproductive-Age+Mice.">Manipulation of Ovarian Function Significantly Influenced Sarcopenia in Postreproductive-Age Mice.</a> J. Transplant. , (2016).</li><li>Peterson, R. L., Parkinson, K. C., Mason, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Restoration+of+immune+and+renal+function+in+aged+females+by+re-establishment+of+active+ovarian+function.">Restoration of immune and renal function in aged females by re-establishment of active ovarian function.</a> Reprod. Fertil. Dev. , (2017).</li><li>Parkinson, K. C., Peterson, R. L., Mason, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+behavior+and+sensory+function+were+significantly+influenced+by+restoration+of+active+ovarian+function+in+postreproductive+mice.">Cognitive behavior and sensory function were significantly influenced by restoration of active ovarian function in postreproductive mice.</a> Exp. Geront. 92, 28-33 (2017).</li><li>Cargill, S. L., Carey, J. R., Muller, H. G., Anderson, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+of+ovary+determines+remaining+life+expectancy+in+old+ovariectomized+mice.">Age of ovary determines remaining life expectancy in old ovariectomized mice.</a> Aging Cell. 2 (3), 185-190 (2003).</li><li>Brooks, H. L., Pollow, D. P., Hoyer, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+VCD+Mouse+Model+of+Menopause+and+Perimenopause+for+the+Study+of+Sex+Differences+in+Cardiovascular+Disease+and+the+Metabolic+Syndrome.">The VCD Mouse Model of Menopause and Perimenopause for the Study of Sex Differences in Cardiovascular Disease and the Metabolic Syndrome.</a> Physiology. 31 (4), 250-257 (2016).</li><li>Rivera, Z., Christian, P. J., Marion, S. L., Brooks, H. L., Hoyer, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Steroidogenic+Capacity+of+Residual+Ovarian+Tissue+in+4-Vinylcyclohexene+Diepoxide-Treated+Mice.">Steroidogenic Capacity of Residual Ovarian Tissue in 4-Vinylcyclohexene Diepoxide-Treated Mice.</a> Biol. Reprod. 80 (2), 328-336 (2009).</li><li>Yuan, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging+in+inbred+strains+of+mice:+study+design+and+interim+report+on+median+lifespans+and+circulating+IGF1+levels.">Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels.</a> Aging Cell. 8 (3), 277-287 (2009).</li><li>Mason, J. B., Cargill, S. L., Anderson, G. B., Carey, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transplantation+of+Young+Ovaries+to+Old+Mice+Increased+Life+Span+in+Transplant+Recipients.">Transplantation of Young Ovaries to Old Mice Increased Life Span in Transplant Recipients.</a> J. Gerontol. A Biol. Sci. Med. Sci. 64 (12), 1207-1211 (2009).</li><li>Harrison, D. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acarbose,+17-alpha-estradiol,+and+nordihydroguaiaretic+acid+extend+mouse+lifespan+preferentially+in+males.">Acarbose, 17-alpha-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males.</a> Aging Cell. 13 (2), 273-282 (2013).</li><li>Manay, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=17&#945;-Estradiol+Attenuates+Neuron+Loss+in+Ovariectomized+Dtg+A&#946;PP/PS1+Mice.">17&#945;-Estradiol Attenuates Neuron Loss in Ovariectomized Dtg A&#946;PP/PS1 Mice.</a> J. Alzheimers Dis. 23 (4), 629-639 (2011).</li><li>Parker, W. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ovarian+conservation+at+the+time+of+hysterectomy+and+long-term+health+outcomes+in+the+nurses'+health+study.">Ovarian conservation at the time of hysterectomy and long-term health outcomes in the nurses' health study.</a> Obstet Gynecol. 113, 1027-1037 (2009).</li></ol>

The authors have nothing to disclose.

Ovariectomy and transplantation of intact and germ cell-depleted ovaries have been conducted in mice ranging from 21 days to 18 months of age. When performing an ovariectomy where it is desirable to maintain the ovarian bursa intact, care must be taken when incising the bursal tissue. In mice older than six months of age, much of the bursa becomes overlaid with the fat pad, which limits the areas that can be used for access. In these cases, it is often advantageous to tear the bursa open close to the fat pad border. This...

The influence of reproduction on health and life span is often mistakenly thought of as restricted only to the period encompassing reproductive competency. While the lifestyle and phenotypes associated with the reproductively competent phase of the life span are easily differentiated from the pre- and postreproductive phases, reproductive status influences health throughout all phases of the life span. The period of reproductive competency is often referred to as the reproductive life span, differentiating itself from the chronological life span. This terminology lends itself to an artificial separation of the two life-span designations when in reality, both are closely tied to each other with events affecting one, more often than not, affecting the other as well.
Evidence over the past decade indicates that an individual&#39;s reproductive status is associated with an increased risk of developing chronic health conditions1. One study documented an association between shorter life spans and reproductive failure for a cohort of men2. The association is even more striking in women. Cardiovascular disease is rare in premenopausal women3, but ovarian failure increases cardiovascular disease sharply at menopause4 and in young women with premature ovarian failure5. Insulin resistance6 and bone loss increase at menopause7 and almost two-thirds of Americans with Alzheimer&#39;s disease are women8. Well-defined changes in ovarian signaling mark the transition from a premenopausal, disease-resistant state, to a postmenopausal, disease-burdened state. This stable transition, presents an opportunity to identify mechanisms that accelerate disease risks in aging.
Recently, transplantation of cryopreserved ovarian tissue has been used to restore fertility in women that undergo medical procedures which may endanger the germ line cells, such as chemotherapy. Transplantation of ovarian tissue can also be used to produce viable offspring in animals with non-ovarian based infertility, including transgenic mice9. Ovarian transplantation is an efficient method to separate the influence of reproductive function or reproductive aging from chronological aging per se.
The well-established supportive role for ovarian hormones in many aspects of female health implicates the loss of hormone production from actively cycling germ cells, as the principal cause of increased disease risks at menopause. While the value of ovarian hormones in female health is unquestionable, replacing these hormones in peri- and postmenopausal women has been unreliable in restoration of the health benefits enjoyed by young women with young ovaries. These health benefits are reliably restored by heterochronic transplantation of young ovaries to postreproductive female mice10,11,12,13,14.
Reproductive status of both donor and recipient mice should be determined prior to and after transplantation or ovariectomy procedures. Presumptive postreproductive mice that display signs of gonadal input prior to surgery at 12 months of age are excluded from these experiments. Gonadal input is determined by vaginal cytology. Data on vaginal cytology are collected for at least 10 consecutive days pre-surgery to ensure a postreproductive state in recipient mice and actively-cycling ovaries in donor mice. One estrous cycle is defined as the period from the day nucleated epithelial cells first appear (i.e., proestrus) to the day preceding the next appearance of nucleated epithelial cells in the vaginal smear, provided that there is a period of leukocytic presence (i.e., diestrus) in between. Estrus is determined by the presence of large, squamous epithelial cells, with or without nuclei. Mice that display no cyclic activity for a 10 day period before and/or after surgery are determined to have no gonadal input for said period. Mice that display at least one full estrous cycle in a 10 day period before and/or after surgery are determined to have gonadal input for said period. Female mice should be housed in the presence of male mice or exposed to soiled bedding from a male&#39;s cage to ensure consistent exposure to cycle-inducing stimuli.
These transplantation procedures are most efficiently accomplished with two surgeons working simultaneously on donor and recipient mice. However, the procedures are easily accomplished by one surgeon, with the donor ovaries most often recovered prior to beginning the ovariectomy procedure on the recipient mouse. This protocol describes the procedure for the single surgeon. Exposure of the reproductive tract and closure of the site is normally done without a microscope, whereas the removal and replacement of the ovaries is done under a microscope. As with learning any surgical procedure, incision sites may be larger and surgeries may take longer while first learning the procedure and will generally decrease with experience.

<table>
	<tbody>
		<tr>
			<td>Dissecting microscope</td>
			<td>Any dissecting scope with an adjustable working distance.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Warm Water Recirculator and appropriate pad for your size surgical/recovery field.</td>
			<td>Stryker/Gaymar</td>
			<td>TP700</td>
			<td>Circulating water pads produce even and consistent temperature operating and recovery fields.</td>
		</tr>
		<tr>
			<td>Surgical instruments-dissection instruments for access to the reproductive tract</td>
			<td></td>
			<td></td>
			<td>Choice of specific surgical instruments is highly surgeon-specific</td>
		</tr>
		<tr>
			<td>Surgical instruments-fine instruments for the transplantation procedure.</td>
			<td></td>
			<td></td>
			<td>Choice of specific surgical instruments is highly surgeon-specific</td>
		</tr>
		<tr>
			<td>Suture material for abdominal wall</td>
			<td>eSutures</td>
			<td>G3756K: 6-0 MILD CHROMIC GUT 18&#34; HE-7 CUTTING, DOUBLE ARMED</td>
			<td></td>
		</tr>
		<tr>
			<td>Suture material for ovarian bursa</td>
			<td>eSutures</td>
			<td>2809G: 9-0 or 2810G: 10-0 ETHILON BLACK 5&#34; BV130-5 TAPER</td>
			<td>10-0 suture can be difficult to locate if dropped on the surgery field.</td>
		</tr>
		<tr>
			<td>Absorbable gelatin sponge</td>
			<td>PFIZER.</td>
			<td>Gelfoam- PFIZER 09-0315-08.</td>
			<td>cut into small (~2mm) pieces under sterile conditions.</td>
		</tr>
		<tr>
			<td>Staples for skin closure</td>
			<td>Becton Dickinson</td>
			<td>MikRon Autoclip 9mm (BD 427631)</td>
			<td></td>
		</tr>
		<tr>
			<td>Eye ointment.</td>
			<td>MWI Veterinary Supply Co.</td>
			<td>Puralube sterile opthalmic ointment</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringes for anesthesia, analgesia and epinephrine</td>
			<td>MWI Veterinary Supply Co.</td>
			<td>BD 305536</td>
			<td>27g x 3/8in,Intradermal Bevel 1/2ml</td>
		</tr>
		<tr>
			<td>Syringes for saline.</td>
			<td>MWI Veterinary Supply Co.</td>
			<td>BD 309657.</td>
			<td>3ml syringe, luer-lok tip, 27g needle</td>
		</tr>
		<tr>
			<td>Clippers/blade</td>
			<td>Andis</td>
			<td>Super AGR+&#8482; Cordless Detachable Blade Clipper and a CeramicEdge&#174; #40 blade.</td>
			<td>Any clippers with a fine blade.</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>University chemical supply</td>
			<td></td>
			<td>dilute to 70% for use.</td>
		</tr>
		<tr>
			<td>Betadine solution</td>
			<td>MWI Veterinary Supply Co.</td>
			<td>003233</td>
			<td></td>
		</tr>
		<tr>
			<td>2x2 gauze pads</td>
			<td>MWI Veterinary Supply Co.</td>
			<td>003073</td>
			<td>autoclaved with surgery packs</td>
		</tr>
		<tr>
			<td>Borosilicate glass beads</td>
			<td>Sigma-Aldrich Co.</td>
			<td>Z273619</td>
			<td>Autoclave in sintilation vials</td>
		</tr>
		<tr>
			<td>4-vinylcyclohexene diepoxide</td>
			<td>Sigma-Aldrich Co.</td>
			<td>94956</td>
			<td></td>
		</tr>
		<tr>
			<td>Sesame oil</td>
			<td>Sigma-Aldrich Co.</td>
			<td>S3547</td>
			<td></td>
		</tr>
	</tbody>
</table>

orthotopic ovarian transplantation procedures to investigate the life- and health-span influence of ovarian senescence in female mice

Ovarian transplantation was first conducted at Utah State University in 1963. In more recent work, heterochronic transplantation of mammalian ovaries is being used to investigate the health-protective effects of young ovaries in young females. The current procedures employ an orthotopic transplantation method, where allogenic ovaries are transplanted back to their original position in the ovarian bursa. This is in contrast to the more commonly used heterotopic transplantation of ovaries/ovarian tissue subcutaneously or under the kidney capsule. All three locations provide efficient revascularization of the transplanted tissues. However, orthotopic transplantation provides the ovary with the most natural signaling environment and is the only procedure that provides the opportunity for the animal to reproduce naturally post-operatively. One must take care to remove all endogenous ovarian tissue during the ovariectomy procedure. If any endogenous tissue remains or if only one ovary is removed, the transplanted tissue will remain dormant until the existing tissue becomes senescent. While revascularization of the transplanted ovaries occurs very quickly, the transplant recipient can take a considerable amount of time to adapt to a new hypothalamic/pituitary/gonadal/adrenal (HPG/A) axis signaling regime associated with the transplanted tissue. This normally takes about 100 days in the mouse. Therefore, transplantation experiments should be designed to accommodate this adaptation period. Typical results with ovarian transplantation will include changes in the health of the recipient that reflect the age of the transplanted ovary, rather than the chronological age of the recipient.

Ovariectomy at 21 days of age will avoid major up-regulation of the reproductive system at the onset of puberty and eliminate other influences the female gonad might have in addition to direct effects of gonadal hormones. Reproductive decline in CBA/J mice usually begins with irregular cycles at 8-10 months of age. At 11 months of age, most females in this line of mice have reached a point of reproductive failure15 with a complete loss of responsive oocytes by 12 m...

Watch this Scientific Journal Video about Orthotopic Ovarian Transplantation Procedures to Investigate the Life- and Health-span Influence of Ovarian Senescence in Female Mice at JoVE.com

Orthotopic Ovarian Transplantation Procedures to Investigate the Life- and Health-span Influence of Ovarian Senescence in Female Mice

Described here are orthotopic ovarian transplantation protocols for modifying ovarian influence on the physiology of the recipient mouse. This surgical procedure is used to expose female mice to various types of ovarian influence and may include heterochronic transplantations and transplantation of ovaries that have undergone various ex vivo treatments.

Ovarian transplantation was first conducted at Utah State University in 1963. In more recent work, heterochronic transplantation of mammalian ovaries is ...

orthotopic-ovarian-transplantation-procedures-to-investigate-life

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JoVE Journal

Developmental Biology

10.7K Views.  Utah State University. Described here are orthotopic ovarian transplantation protocols for modifying ovarian influence on the physiology of the recipient mouse. This surgical procedure is used to expose female mice to various types of ovarian influence and may include heterochronic transplantations and transplantation of ovaries that have undergone various ex vivo treatments.

Video: Orthotopic Ovarian Transplantation Procedures to Investigate the Life- and Health-span Influence of Ovarian Senescence in Female Mice

Culture and Co-Culture of Mouse Ovaries and Ovarian Follicles

The mammalian ovary is composed of ovarian follicles, each follicle consisting of a single oocyte surrounded by somatic granulosa cells, enclosed together within a basement membrane. A finite pool of follicles is laid down during embryonic development, when oocytes in meiotic arrest form a close association with flattened granulosa cells, forming primordial follicles. By or shortly after birth, mammalian ovaries contain their lifetime&#8217;s supply of primordial follicles, from which point onwards there is a steady release of follicles into the growing follicular pool.
The ovary is particularly amenable to development in vitro, with follicles growing in a highly physiological manner in culture. This work describes the culture of whole neonatal ovaries containing primordial follicles, and the culture of individual ovarian follicles, a method which can support the development of follicles from an immature through to the preovulatory stage, after which their oocytes are able to undergo fertilization in vitro. The work outlined here uses culture systems to determine how the ovary is affected by exposure to external compounds. We also describe a co-culture system, which allows investigation of the interactions that occur between growing follicles and the non-growing pool of primordial follicles.

This protocol describes the primary culture/co-culture of mouse ovarian tissue, using ovaries from neonatal mice and individual ovarian follicles from prepubertal mice. The culture techniques support development in a highly physiological manner, allowing investigation of the effect of extrinsic agents on the ovary, and of interactions between ovarian follicles.

The mammalian ovary is composed of ovarian follicles, each follicle consisting of a single oocyte surrounded by somatic granulosa cells, enclosed together ...

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the large size of their cells in early embryos, make Xenopus laevis a useful model for visualising GFP-tagged ligands. Synthetic mRNAs are efficiently translated after injection into early stage Xenopus embryos, and injections can be targeted to a single cell. When combined with a lineage tracer such as membrane tethered RFP, the injected cell (and its descendants) that are producing the overexpressed protein can easily be followed. This protocol describes a method for the production of fluorescently tagged Wnt and Shh ligands from injected mRNA. The methods involve the micro dissection of ectodermal explants (animal caps) and the analysis of ligand diffusion in multiple samples. By using confocal imaging, information about ligand secretion and diffusion over a field of cells can be obtained. Statistical analyses of confocal images provide quantitative data on the shape of ligand gradients. These methods may be useful to researchers who want to test the effects of factors that may regulate the shape of morphogen gradients.

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

The manuscript here provides a simple set of methods for analysing the secretion and diffusion of fluorescently tagged ligands in Xenopus. This provides a context for testing the ability of other proteins to modify ligand distribution and allowing experiments that may give insight into mechanisms regulating morphogen gradients.

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the ...

Imaging of Cell Shape Alteration and Cell Movement in Drosophila Gastrulation Using DE-cadherin Reporter Transgenic Flies

Gastrulation is the first set of morphologically dynamic events that occur during the embryonic development of multicellular animals such as Drosophila. This morphological alteration is also recognized as epithelial to mesenchymal transition (EMT). Dysregulation of EMT is associated with fibrosis and cancer metastasis. There is emerging evidence that EMT is controlled by a number of molecular mechanisms. As such, many key genes that control apical constriction are also known to be important factors in the EMT observed in cancer metastasis. Like EMT during Drosophila gastrulation, epithelial cells can be induced to change their shape and be reprogrammed to redirect cell fate towards various other cell types. Here we provide a robust imaging method of Drosophila gastrulation to assay the initiation of morphogenetic cellular movements and cell fate identification during this stage of embryonic development. Using this method, we identify cell rearrangement at the time of gastrulation and demonstrate the importance of apical constriction during gastrulation using GFP labeled DE-cadherin.

Imaging of Cell Shape Alteration and Cell Movement in Drosophila Gastrulation Using DE-cadherin Reporter Transgenic Flies

Herein we describe a procedure to capture live images of Drosophila gastrulation. This has enabled us to better understand the apical constriction involved in early development and further analyze mechanisms governing cellular movements during tissue structure modification.

Gastrulation is the first set of morphologically dynamic events that occur during the embryonic development of multicellular animals such as Drosophila. ...

A Novel Mammary Fat Pad Transplantation Technique to Visualize the Vessel Generation of Vascular Endothelial Stem Cells

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper vessel development and homeostasis. However, studies on endothelial lineage hierarchy remain elusive due to the lack of tools to gain access as well as to directly evaluate their behavior in vivo. To address this shortcoming, a new tissue model to study angiogenesis using the mammary fat pad has been developed. The mammary gland develops mostly in the postnatal stages, including puberty and pregnancy, during which robust epithelium proliferation is accompanied by extensive vascular remodeling. Mammary fat pads provide space, matrix, and rich angiogenic stimuli from the growing mammary epithelium. Furthermore, mammary fat pads are located outside the peritoneal cavity, making them an easily accessible grafting site for assessing the angiogenic potential of exogenous cells. This work also describes an efficient tracing approach using fluorescent reporter mice to specifically label the targeted population of vascular endothelial stem cells (VESCs) in vivo. This lineage tracing method, coupled with subsequent tissue whole-mount microscopy, enable the direct visualization of targeted cells and their descendants, through which the proliferation capability can be quantified and the differentiation commitment can be fate-mapped. Using these methods, a population of bipotent protein C receptor (Procr) expressing VESCs has recently been identified in multiple vascular systems. Procr+ VESCs, giving rise to both new ECs and pericytes, actively contribute to angiogenesis during development, homeostasis, and injury repair. Overall, this manuscript describes a new mammary fat pad transplantation and in vivo lineage tracing techniques that can be used to evaluate the stem cell properties of VESCs.

This work demonstrates a novel approach to assess the proliferation, differentiation, and vessel-forming potential of vascular endothelial stem cells (VESCs) through mammary fat pad transplantation followed by whole-mount tissue preparation for microscopic observation. A lineage tracing strategy to investigate the behavior of VESCs in vivo is also presented.

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper ...

Evaluation of Injury-induced Senescence and In Vivo Reprogramming in the Skeletal Muscle

Cellular senescence is a stress response that is characterized by a stable cellular growth arrest, which is important for many physiological and pathological processes, such as cancer and ageing. Recently, senescence has also been implicated in tissue repair and regeneration. Therefore, it has become increasingly critical to identify senescent cells in vivo. Senescence-associated &#946;-galactosidase (SA-&#946;-Gal) assay is the most widely used assay to detect senescent cells both in culture and in vivo. This assay is based on the increased lysosomal contents in the senescent cells, which allows the histochemical detection of lysosomal &#946;-galactosidase activity at suboptimum pH (6 or 5.5). In comparison with other assays, such as flow cytometry, this allows the identification of senescent cells in their resident environment, which offers valuable information such as the location relating to the tissue architecture, the morphology, and the possibility of coupling with other markers via immunohistochemistry&#160;(IHC). The major limitation of the SA-&#946;-Gal assay is the requirement of fresh or frozen samples.
Here, we present a detailed protocol to understand how cellular senescence promotes cellular plasticity and tissue regeneration in vivo. We use SA-&#946;-Gal to detect senescent cells in the skeletal muscle upon injury, which is a well-established system to study tissue regeneration. Moreover, we use&#160;IHC to detect Nanog, a marker of pluripotent stem cells, in a transgenic mouse model. This protocol enables us to examine and quantify cellular senescence in the context of induced cellular plasticity and in vivo reprogramming.

Evaluation of Injury-induced Senescence and In Vivo Reprogramming in the Skeletal Muscle

Here we present a detailed protocol to detect both senescent and pluripotent stem cells in the skeletal muscle upon injury while inducing in vivo reprogramming. This method is suitable for evaluating the role of cellular senescence during tissue regeneration and reprogramming in vivo.

Cellular senescence is a stress response that is characterized by a stable cellular growth arrest, which is important for many physiological and ...

Methods for Imaging Intracellular pH of the Follicle Stem Cell Lineage in Live Drosophila Ovarian Tissue

Changes in intracellular pH (pHi) play important roles in the regulation of many cellular functions, including metabolism, proliferation, and differentiation. Typically, pHi dynamics are determined in cultured cells, which are amenable to measuring and experimentally manipulating pHi. However, the recent development of new tools and methodologies has made it possible to study pHi dynamics within intact, live tissue. For Drosophila research, one important development was the generation of a transgenic line carrying a pHi biosensor, mCherry::pHluorin. Here, we describe a protocol that we routinely use for imaging live Drosophila ovarioles to measure pHi in the epithelial follicle stem cell (FSC) lineage in mCherry::pHluorin transgenic wild type lines; however, the methods described here can be easily adapted for other tissues, including the wing discs and eye epithelium. We describe techniques for expressing mCherry::pHluorin in the FSC lineage, maintaining ovarian tissue during live imaging, and acquiring and analyzing images to obtain pHi values.

Methods for Imaging Intracellular pH of the Follicle Stem Cell Lineage in Live Drosophila Ovarian Tissue

We provide a protocol for imaging intracellular pH of an epithelial stem cell lineage in live Drosophila ovarian tissue. We describe methods to generate transgenic flies expressing a pH biosensor, mCherry::pHluorin, image the biosensor using quantitative fluorescence imaging, generate standard curves, and convert fluorescence intensity values to pH values.

Changes in intracellular pH (pHi) play important roles in the regulation of many cellular functions, including metabolism, proliferation, and ...

Collection of Post-mating Semen from the Female Reproductive Tract and Measurement of Semen Liquefaction in Mice

In mice, ejaculated semen is deposited in the uterus. After ejaculation, the semen changes consistency from gel-like to watery, a process called liquefaction. In this study, we show how to collect the post-ejaculated semen from the female reproductive tract in a mouse model. First, adult female mice in the estrus stage were housed in a male&#39;s cage overnight. The next morning, copulation was confirmed by the presence of copulatory plug at the vaginal opening. Female mice with copulatory plugs were euthanized, and each reproductive tract was collected as a whole (vagina, uterus, oviducts, ovaries), ensuring a closed system to contain the semen. The reproductive tract was placed in a 1.5 mL microcentrifuge tube, and the vagina was cut off to release the semen into the tube. To ensure maximum semen volume for analysis, toothless forceps were used to squeeze the uterine horns from ovarian end to vaginal end expelling remaining semen. The whole reproductive tract was then discarded. The semen-containing tube was briefly spun down. A 25 &#956;L capillary pipette was placed into the tube at a 180&#176; angle (parallel to the tube wall). The amount of time used to fill the capillary tube to the 25 &#956;L line was recorded. Semen from a proven male breeder usually takes approximately 60-180 s to fill a 25 &#956;L capillary tube. This semen collection technique can also be used in other downstream applications such as sperm imaging and motility analysis.

Semen liquefaction is required for sperm to be liberated from the seminal gel. This study provides the procedures for collecting semen from the female reproductive tract post-coitus, and measuring semen liquefaction time.

In mice, ejaculated semen is deposited in the uterus. After ejaculation, the semen changes consistency from gel-like to watery, a process called ...

Induction and Validation of Cellular Senescence in Primary Human Cells

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a hallmark of various pathophysiological conditions including tumor suppression, tissue remodeling and aging. The inducers of cellular senescence in vivo are still poorly characterized. However, a number of stimuli can be used to promote cellular senescence ex vivo. Among them, most common senescence-inducers are replicative exhaustion, ionizing and non-ionizing radiation, genotoxic drugs, oxidative stress, and demethylating and acetylating agents. Here, we will provide detailed instructions on how to use these stimuli to induce fibroblasts into senescence. This protocol can easily be adapted for different types of primary cells and cell lines, including cancer cells. We also describe different methods for the validation of senescence induction. In particular, we focus on measuring the activity of the lysosomal enzyme Senescence-Associated &#946;-galactosidase (SA-&#946;-gal), the rate of DNA synthesis using 5-ethynyl-2&#39;-deoxyuridine (EdU) incorporation assay, the levels of expression of the cell cycle inhibitors p16 and p21, and the expression and secretion of members of the Senescence-Associated Secretory Phenotype (SASP). Finally, we provide example results and discuss further applications of these protocols.

Here, we discuss a series of protocols for induction and validation of cellular senescence in cultured cells. We focus on different senescence-inducing stimuli and describe the quantification of common senescence-associated markers. We provide technical details using fibroblasts as a model, but the protocols can be adapted to various cellular models.

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a ...

Ovarian Tissue Culture to Visualize Phenomena in Mouse Ovary

Mammalian females periodically ovulate an almost constant number of oocytes during each estrus cycle. To sustain such regularity and periodicity, regulation occurs at the hypothalamic-pituitary-gonadal axis level and on developing follicles in the ovary. Despite active studies, follicle development mechanisms are not clear because of the several steps involved from the dormant primordial follicle activation to ovulation, and because of the regulation complexity that differs at each follicular stage. To investigate the mechanisms of follicle development, and the dynamics of follicles throughout the estrus cycle, we developed a mouse ovarian tissue culture model that can be used to observe follicle development using a microscope. Systematic follicle development, periodical ovulation, and follicle atresia can all be reproduced in the cultured ovary model, and the culture conditions can be experimentally modulated. Here, we demonstrate the usefulness of this method in the study of the regulatory mechanisms of follicle development and other ovarian phenomena.

Ovarian tissue cultures can be used as models of follicle development, ovulation, and follicle atresia and indicate regulatory mechanisms of dynamic ovarian processes.

Mammalian females periodically ovulate an almost constant number of oocytes during each estrus cycle. To sustain such regularity and periodicity, ...

A Quantitative Measurement of Reactive Oxygen Species and Senescence-associated Secretory Phenotype in Normal Human Fibroblasts During Oncogene-induced Senescence

Cellular senescence has been considered a state of irreversible growth arrest upon exhaustion of proliferative capacity or exposure to various stresses. Recent studies have extended the role of cellular senescence to various physiological processes, including development, wound healing, immune surveillance, and age-related tissue dysfunction. Although cell cycle arrest is a critical hallmark of cellular senescence, an increased intracellular reactive oxygen species (ROS) production has also been demonstrated to play an important role in the induction of cellular senescence. In addition, recent studies revealed that senescent cells exhibit potent paracrine activities on neighboring cells and tissues through a senescence-associated secretory phenotype (SASP). The sharp increase in interest regarding therapeutic strategies against cellular senescence emphasizes the need for a precise understanding of senescence mechanisms, including intracellular ROS and the SASP. Here, we describe protocols for quantitatively assessing intracellular ROS levels during H-Ras-induced cellular senescence using ROS-sensitive fluorescent dye and flow cytometry. In addition, we introduce sensitive techniques for the analysis of the induction of mRNA expression and secretion of SASP factors. These protocols can be applied to various cellular senescence models.

Intracellular ROS has been shown to play an important role in the induction of cellular senescence. Here, we describe a sensitive assay for quantifying ROS levels during cellular senescence. We also provide protocols for assessing the senescence-associated secretory phenotype, which reportedly contributes to various age-related dysfunctions.

Cellular senescence has been considered a state of irreversible growth arrest upon exhaustion of proliferative capacity or exposure to various stresses. ...