Effect of actin polymerization inhibitor during oocyte maturation on parthenogenetic embryo development and ploidy in Capra hircus

Paternally and maternally imprinted gene perturbed expression in parthenogenetic diploid embryos in Capra hircus

The present research work was undertaken to compare the expression of paternally imprinted (P57KIP2, Grb10 and Xist) and maternally imprinted gene (Dlk1) among diploid parthenogenetic (DIP), female sexed in vivo and female sexed in vitro produced embryonic cell colony. The good quality caprine oocytes were matured in presence of cytochalasin B (CCB) and activated by ethanol (7%) for 5 min followed by incubation with 2 mM 6-dimethyl amino purine (DMAP) for 4 h for DIP embryos production. In vivo embryo was collected by surgical method from 10 super ovulated goats using Pluset®. In vitro embryos were produced by maturation of good quality oocyte followed by fertilization with superior male germplasm from the institute flock. Embryonic cell colony were developed from 8 to 16 and morula stage DIP, IVF and in vivo derived embryos. These colonies were used for studying the paternal and maternal imprinted genes expression. Karyotyping and sexing of embryonic cell colony was done to get only female sexed colony for this purpose. Paternally imprinted genes (P57KIP2, Grb10 and Xist) showed more expression in DIP compared to in vivo and IVF derived embryonic cell colony. The expression of maternally imprinted genes (Dlk1) was low in DIP compared to in vivo and IVF derived embryonic cell colony. The present study demonstrated that the expression profile of both paternal and maternally imprinted genes were perturbed, which may be responsible for developmental failure of parthenogenetic embryos to full term following parthenogenetic embryo transfer in goat.

Transcriptome analysis of differentially expressed genes in rabbits' ovaries by digital gene-expression profiling

Reproduction is a complex physiological process that is regulated by multiple genes and pathways. Compared with studies of common livestock, fewer studies of genes related to the fertility of rabbits (Oryctolagus cuniculus) have been reported, and the molecular mechanism of their high productivity is still poorly understood. To identify candidate genes associated with development and prolificacy in rabbits, we analyzed gene expression differences among the ovaries of mature Californian rabbit (LC), and mature (HH) and immature Harbin white rabbit (IH) using digital gene expression technology. We detected 885 and 321 genes that were significantly differentially expressed in comparisons between HH/IH and HH/LC, respectively. The functions of the differentially expressed genes (DEGs) were determined by GO classification and KEGG pathway analysis. The results suggest that most of the DEGs between the mature and immature developmental stages were predominantly associated with DNA replication, cell cycle, and progesterone-mediated oocyte maturation, and most were up-regulated in the IH group compared with the HH group. The DEGs involved in disparate fecundities between HH and LC were associated with reproduction, fructose and mannose metabolism, steroid hormone biosynthesis, and pyruvate metabolism. Our results will contribute to a better understanding of changes in the regulatory network in ovary at different developmental stages and in different fertility of rabbit.

Identification of differentially-expressed genes in early developmental ovary of Yellow River carp (Cyprinus carpio var) using Suppression Subtractive Hybridization

Ovary development appears to be under polygenic control, and is influenced by multiple genetic factors that may vary from organism to organism. To gain a better insight into the molecular mechanisms of carp ovary development, Suppression Subtractive Hybridization (SSH) DNA libraries in two species of Yellow River carp were analyzed. Primordial gonads and stage II ovaries were used as testers, and adult ovaries as drivers. One hundred and fifty differentially-expressed candidate genes were examined by Southern blot microarray hybridization. We identified 41 differentially-expressed genes in the PG (Primordial gonad) library and 37 in the stage II ovary library. Gene Ontology Biological Pathway analysis showed the genes were involved in signal transduction, proteolysis process, cell differentiation, TGF-β signal and other biological responses. Twenty-two candidate genes were selected and further characterized using qRT-PCR. Pvalb, epd, and MYH were found specifically expressed in PG, while bmp2b, desmin and fp1 were specifically expressed in stage II ovary. Our results indicate that these genes could be used as biomarkers of the early development of carp ovary. This finding will provide a basis for further understanding of the complex gonad developmental molecular mechanisms in Yellow River carp.

Transcriptome analysis of the Capra hircus ovary

BACKGROUND

Capra hircus is an important economic livestock animal, and therefore, it is necessary to discover transcriptome information about their reproductive performance. In this study, we performed de novo transcriptome sequencing to produce the first transcriptome dataset for the goat ovary using high-throughput sequencing technologies. The result will contribute to research on goat reproductive performance.

METHOD AND RESULTS

RNA-seq analysis generated more than 38.8 million clean paired end (PE) reads, which were assembled into 80,069 unigenes (mean size = 619 bp). Based on sequence similarity searches, 64,824 (60.6%) genes were identified, among which 29,444 and 11,271 unigenes were assigned to Gene Ontology (GO) categories and Clusters of Orthologous Groups (COG), respectively. Searches in the Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG) showed that 27,766 (63.4%) unigenes were mapped to 258 KEGG pathways. Furthermore, we investigated the transcriptome differences of goat ovaries at two different ages using a tag-based digital gene expression system. We obtained a sequencing depth of over 5.6 million and 5.8 million tags for the two ages and identified a large number of genes associated with reproductive hormones, ovulatory cycle and follicle. Moreover, many antisense transcripts and novel transcripts were found; clusters with similar differential expression patterns, enriched GO terms and metabolic pathways were revealed for the first time with regard to the differentially expressed genes.

CONCLUSIONS

The transcriptome provides invaluable new data for a functional genomic resource and future biological research in Capra hircus, and it is essential for the in-depth study of candidate genes in breeding programs.