Analysis of molecular mechanism for acceleration of polyembryony using gene functional annotation pipeline in Copidosoma floridanum

Background: Polyembryony is defined as the formation of several embryos from a single egg. This phenomenon can occur in humans, armadillo, and some endoparasitoid insects. However, the mechanism underlying polyembryogenesis in animals remains to be elucidated. The polyembryonic parasitoid wasp Copidosoma floridanum oviposits its egg into an egg of the host insect; eventually, over 2,000 individuals will arise from one egg. Previously, we reported that polyembryogenesis is enhanced when the juvenile hormone (JH) added to the culture medium in the embryo culture. Hence, in the present study, we performed RNA sequencing (RNA-Seq) analysis to investigate the molecular mechanisms controlling polyembryogenesis of C. floridanum . Functional annotation of genes is not fully available for C.floridanum ; however, whole genome assembly has been archived. Hence, we constructed a pipeline for gene functional annotation in C. floridanum and performed molecular network analysis. We analyzed differentially expressed genes between control and JH-treated molura after 48 h of culture, then used the tblastx program to assign whole C. floridanum transcripts to human gene. Results: We obtained 11,117 transcripts in the JH treatment group and identified 217 differentially expressed genes compared with the control group. As a result, 76% of C. floridanum transcripts were assigned to human genes. Gene enrichment analysis revealed genes associated with platelet degranulation, fatty acid biosynthesis, cell morphogenesis in the differentiation and integrin signaling pathways were fluctuated following JH treatment. Furthermore, Cytoscape analysis revealed a molecular interaction that was possibly associated with polyembryogenesis . Conclusions: We have constructed a pipeline for gene functional annotation of C. floridanum , and identified transcripts with high similarity to human genes during early embryo developmental. Additionally, this study reveals new molecular interactions associated with polyembryogenesis; these interactions could indicate the molecular mechanisms underlying polyembryony. Our results highlight the potential utility of molecular interaction analysis in human twins.

Analysis of molecular mechanism for acceleration of polyembryony using gene functional annotation pipeline in Copidosoma floridanum

Background: Polyembryony is defined as the formation of several embryos from a single egg. This phenomenon can occur in humans, armadillo, and some endoparasitoid insects. However, the mechanism underlying polyembryogenesis in animals remains to be elucidated. The polyembryonic parasitoid wasp Copidosoma floridanum oviposits its egg into an egg of the host insect; eventually, over 2,000 individuals will arise from one egg. Previously, we reported that polyembryogenesis is enhanced when the juvenile hormone (JH) added to the culture medium in the embryo culture. Hence, in the present study, we performed RNA sequencing (RNA-Seq) analysis to investigate the molecular mechanisms controlling polyembryogenesis of C. floridanum . Functional gene annotation is not available for C. floridanum because whole-genome sequencing has not been achieved. Hence, we constructed a pipeline for gene functional annotation in C. floridanum and performed molecular network analysis. We analyzed differentially expressed genes between control and JH-treated molura after 48 h of culture, then used the tblastx program to assign whole C. floridanum transcripts to human gene. Results: We obtained 11,117 transcripts in the JH treatment group and identified 217 differentially expressed genes compared with the control group. As a result, 76% of C. floridanum transcripts were assigned to human genes. Gene enrichment analysis revealed genes associated with platelet degranulation and fatty acid biosynthesis to be upregulated, while cell morphogenesis in the differentiation and integrin signaling pathways were suppressed following JH treatment. Furthermore, Cytoscape analysis revealed a molecular interaction that was possibly associated with polyembryogenesis . Conclusions: We have constructed a pipeline for gene functional annotation of C. floridanum , and identified transcripts with high homology to human genes during early embryo developmental. Additionally, this study reveals new molecular interactions associated with polyembryogenesis; these interactions could indicate the molecular mechanisms underlying polyembryony. Our results highlight the potential utility of molecular interaction analysis in human twins.

Analysis of molecular mechanism for acceleration of polyembryony using gene functional annotation pipeline in Copidosoma floridanum

Background: Polyembryony, when several embryos are clonally produced from a single egg, is found in humans, armadillo, and some endoparasitoid insects. Thus, although polyembryony is conserved through insects to mammals, the polyembryogenesis progress remains obscure in these animals. The polyembryonic parasitoid wasp Copidosoma floridanum oviposits its egg into the host insect egg, and, eventually, >2000 individuals occur from one egg. We reported previously that polyembryogenesis was enhanced by juvenile hormone (JH) treatment under the culture condition. Hence, we performed RNA-Seq analysis to elucidate the molecular mechanisms in controlling polyembryogenesis using C. floridanum. Nevertheless, C. floridanum genes do not have a functional gene annotation because of partial whole-genome sequence elucidation. Hence, we constructed a gene functional annotation pipeline for C. floridanum and performed a molecular network analysis in C. floridanum. Results: We extracted fluctuated genes from control and JH treatment molura after 48-h culture to assess molecular mechanisms in polyembryogenesis. Consequently, we obtained 11,117 transcripts and 217 differentially expressed genes in the JH treatment group compared with the control group. Whereas, we used the blastp program to assign whole C. floridanum transcripts to human gene. Remarkably, 76% of C. floridanum transcripts were assigned to human genes. Moreover, we determined platelet degranulation and fatty acid biosynthetic process, suppressing cell morphogenesis involved in the differentiation and integrin signaling pathway by the gene enrichment analysis in the JH treatment group compared with the control group. Furthermore, we noted that molecular interaction possibly associated with polyembryogenesis using Cytoscape. Conclusions: In this study, we constructed C. floridanum gene functional annotation pipeline and C. floridanum transcripts shared with homology to human genes during early embryo developmental stage. Additionally, this study establishes new molecular interactions associated with polyembryogenesis; these molecules could elucidate molecular mechanism in polyembryony, suggesting a possibility of using the molecular interaction in twinning of humans.

Higher aggression towards closer relatives by soldier larvae in a polyembryonic wasp

In the polyembryonic wasp Copidosoma floridanum , females commonly lay one male and one female egg in a lepidopteran host. Both sexes proliferate clonally within the growing host larva. Distinct larval castes develop from each wasp egg, the majority being ‘reproductives’ plus some ‘soldiers’ which sacrifice reproduction and attack competitors. Maturing mixed sex broods are usually female biased, as expected when intra-brood mating is common. Pre-mating dispersal followed by outbreeding is expected to increase sexual conflict over brood sex ratios and result in greater soldier attack rates. Owing to sexually asymmetric relatedness, intra-brood conflicts are expected to be resolved primarily via female soldier attack. We observed soldier behaviour in vitro to test whether lower intra-brood relatedness (siblings from either within-strain or between-strain crosses were presented) increased inter-sexual aggression by female as well as male soldiers. As found in prior studies, females were more aggressive than males but, contrary to expectations and previous empirical observations, soldiers of both sexes showed more aggression towards more closely related embryos. We speculate that lower intra-brood relatedness indicates maternal outbreeding and may suggest a rarity of mating opportunities for reproductives maturing from the current brood, which may enhance the value of opposite sex brood-mates, or that higher aggression towards relatives may be a side-effect of mechanisms to discriminate heterospecific competitors.