Transcriptome analysis of Zi geese (Anser cygnoides) prehierarchical follicles and verification of related genes in arginine metabolic pathway

Abstract

Arginine metabolism plays a pivotal role in the mammalian reproductive system by controlling various
physiological processes of the reproductive organs including follicular development, ovulatory mechanisms and egg
production. However little is known about the molecular mechanisms regulating arginine metabolism at early stages
of folliculogenesis. The objective of the current study was to determine the arginine metabolic pathways in
prehierarchical follicles of Zi geese through the Illumina Hiseq 2500 platform and their transcripts through the de novo
assembly. In this study, five different stages of the geese prehierarchical follicles transcriptome were sequenced. A total
of 31722729162 bp from 224929214 high quality clean sequences was obtained. There were 74.75% transcripts annotated
pathways, and 106 unigenes were mapped in the Arginine and proline metabolism pathway. Combined with Gene
Ontology (GO) functions, ArgE, NOS and ODC were selected as the candidate genes to explore the arginine metabolic
pathway and determine their relative expression in the prehierarchical follicles of geese. The results showed that the
three genes were expressed in all five prehierarchical stages of geese follicles, with the predominant expression in
primary follicles (p ˂ 0.05), indicating promotion of follicular development. This study provides useful inclusive gene
expression profiling information that would certainly provide basic theory for future research studies on follicular
development in Zi geese.