dissection-grading-ovarian-development-wild-type-female

Dissection and Grading of Ovarian Development in Wild-Type Female Insects

Migratory insect pests pose serious challenges to food production and security all over the world. The migratory pests can be monitored and captured using ...

Shandong Academy of Agricultural Sciences

In this study, the complete mitogenome sequence of  was described. The assembled mitogenome is 15,241 bp in length with an extreme bias of high AT content (80.9%) (GenBank accession no. MN747041). The mitochondrial genome contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (12S rRNA and 16S rRNA) genes, and a control region (D-loop region). The mitochondrial gene order was identical to that observed in most lepidopteran genomes, nine PCGs were located on the H-strand, others were located on the L-strand. 12 PCGs were initiated by typical ATN codons, except for  with CGA instead. 21 tRNAs had the typical cloverleaf structure, while the DHU arm of the  gene did not form a stable stem-loop structure. The 'ATAGT(A)'-like motif and a 19 bp poly-T stretch at the down-stream of the  gene were observed in the A + T-rich region. The phylogenetic analysis showed that the relationship of  is very close to the three species in the subfamily Pyraustinae: ,  and , and all the subfamilies of Spilomelinae, Pyraustinae, Crambinae and Nymphulinae within Crambidae formed monophyletic groups with the highest bootstrap value support.

Characterization of the complete mitochondrial genome of Asia Corn Borer,  (Lepidoptera: Crambidae).

Spodoptera frugiperda is a major agricultural pest that has invaded China since January 2019. Given that most of the individuals present in China carried the diagnostic rice-strain mtDNA (COI-RS), there was no efficient method to distinguish populations of S. frugiperda. In this study, we identified and characterized two variant microsatellite alleles in the mitochondrial NAD6 gene of S. frugiperda retrieved from the National Center for Biotechnology Center GenBank. We then sequenced partial NAD6 genes containing the microsatellite region and the diagnostic COI barcoding gene (used to distinguish the corn-strain and the rice-strain) of 429 invasive S. frugiperda individuals that were collected from the main infested regions in China during 2019-2020. Our data indicates that two kinds of interrupted repeat sequences, (ATA)4T(ATA)3 and (ATA)5T(ATA)3, exist in the microsatellite region which we defined as the deletion type (NAD6-D), and the insertion type (NAD6-I) based on the repeat units' differentiation, respectively. The presence of these two microsatellite types in the mtDNA genome of S. frugiperda was further confirmed with the sequencing results in 429 samples. Moreover, NAD6-I and NAD6-D types were both present in individuals with COI-RS, while only NAD6-D type was detected in the COI-CS individuals. Interestingly, the two microsatellite types suggested a possible geographic distribution: the western migratory route (Yunan and Chongqing) was comprised exclusively of NAD6-I type, while both NAD6-I and NAD6-D types were identified in the predicted eastern migration trajectories (Hainan, Guangxi, Shandong, etc.). These results suggested that NAD6-D and NAD6-I types may be useful in distinguishing between populations, analyzing the evolutionary mechanism of mtDNA microsatellite polymorphism, inferring the migratory route of S. frugiperda in China, and developing precise and integrated control strategies for S. frugiperda.

Two Microsatellite Types Within NAD6 Gene Help to Distinguish Populations and Infer the Migratory Route of the Invasive Fall Armyworm, Spodoptera frugiperda, (Lepidoptera, Noctuidae) in China.

Suhong Lv

Institute of Plant Protection

Shandong Academy of Agricultural Sciences

Dissection and Grading of Ovarian Development in Wild-Type Female Insects