Proteomic Analysis of the Follicular Fluid of Tianzhu White Yak during Diestrus

Jinzhong Tao,Guoshun Zhao,Xingxu Zhao,Xiaohu Wu,Fadi Li,Junjie Hu,Yong Zhang

doi:10.3390/ijms15034481

Jinzhong Tao, Guoshun Zhao + Show 5 more

Open Access

https://doi.org/10.3390/ijms15034481

Copy DOI

Abstract

The aim of this study was to identify differentially expressed proteins in the follicular fluid of Tianzhu white yak during diestrus. Follicles obtained from female yak were divided into four groups according to their diameter: 0–2, 2–4, 4–6 mm, and greater than 6 mm. The follicular fluid was directly aspirated from the follicles and mixed according to follicular size, and two-dimensional gel electrophoresis was carried out on the crude follicular fluid samples. Thirty-four differentially expressed spots were generated from these four sizes of follicles. Fourteen of these spots were analyzed by MALDI-TOF/TOF-MS and identified as: AS3MT, VDP, ANKRD6, C10orf107 protein, MRP4, MAPKAP1, AGO3, profilin-β-actin, SPT2 homolog, AGP, AR, RNF20, obscurin-like-1, and one unnamed protein. These proteins were first reported in follicular fluid, in addition to VDP and AGP. Based on existing knowledge of their function and patterns of expression, we hypothesize that most of these differentially expressed proteins play a role in ovarian follicular growth and development, dominant follicle selection, or follicular atresia and development of oocytes; however, the function of the other differentially expressed proteins in reproduction remains ambiguous.

Highlights

The Tianzhu white yak (Poephagus grunniens) inhabits cold prairies above 3000 m, and is a rare and precious local species in Tianzhu Tibetan Autonomous County, China
The ovarian follicle further grows into a mature follicle, after which, together with the follicular fluid, the oocyte is expelled as ovulation proceeds
There are two to three other waves of follicular development in which several oocytes develop to tertiary follicles; usually only one oocyte, sometimes more, develops to the size of a mature follicle, and the others would undergo follicular atresia

Summary

Introduction

The Tianzhu white yak (Poephagus grunniens) inhabits cold prairies above 3000 m, and is a rare and precious local species in Tianzhu Tibetan Autonomous County, China. The number of white yak is decreasing due to their low rate of reproduction [1]. Zhang et al (2006) investigated the breeding conditions of female yaks at the plateau. Female yaks calving a calf biennially, triennially and annually accounted respectively for 88.84%, 9.51% and. 1.65% of the total reproductive females in the heard [6]. The primordial follicle develops into the primary follicle, and into the secondary follicle. The primordial, primary and secondary follicles are called the pre-antral follicle because they are all cavum-absent. The cavity gradually appears and grows bigger as the secondary follicle grows, going from irregular- to crescent-shaped and becomes filled with follicular fluid. The ovarian follicle further grows into a mature follicle, after which, together with the follicular fluid, the oocyte is expelled as ovulation proceeds. There are two to three other waves of follicular development in which several oocytes develop to tertiary follicles; usually only one oocyte, sometimes more, develops to the size of a mature follicle, and the others would undergo follicular atresia

Objectives

Methods

Results

Conclusion