Growth differentiation factor‐9 improves development, mitochondrial activity and meiotic resumption of sheep oocytes after in vitro culture of secondary follicles

Abstract

This study analysed the effect of growth differentiation factor‐9 (GDF‐9) on the in vitro culture of isolated ovine secondary follicles. The follicles were cultured in α‐MEM supplemented with BSA, insulin, glutamine, hypoxanthine, transferrin, selenium, ascorbic acid and FSH (α‐MEM+—control medium) or α‐MEM+ supplemented with 1, 10, 50 or 100 ng/ml GDF‐9. Next, the oocytes were destined to in vitro maturation (IVM). After 12 days of culture, there were no differences regarding the percentage of normal follicles, antrum formation and follicle diameter between the treatments (p > 0.05). The rates of fully grown oocytes (≥110 µm) were higher (p < 0.05) in 100 ng/ml GDF‐9 than other treatments, except for 10 ng/ml of GDF‐9 (p > 0.05). Treatment containing 100 ng/ml GDF‐9 showed higher (p < 0.05) mitochondrial activity than the control group. Moreover, 100 ng/ml GDF‐9 showed more oocytes in MI than α‐MEM+, 1 or 50 ng/ml GDF‐9 (p < 0.05). In conclusion, 100 ng/ml GDF‐9 increased the growth, mitochondrial function and meiotic resumption of oocytes from in vitro grown sheep secondary follicles.

Long non-coding RNA Loc105611671 promotes the proliferation of ovarian granulosa cells and steroid hormone production upregulation of CDC42

“…GCs as the ovarian’s primary functional units, are instrumental in follicular growth and maturation, offering nutritional support and secreting hormones imperative for follicular development ( 5 , 7 , 29 ). Notably, Loc105611671 was identified in the follicles of Qira Black sheep during estrus, implicating a regulatory effect on follicular development through GC modulation ( 27 ).…”

“…As they progress toward ovulation, GCs undergo morphological changes and proliferate ( 4 ). As the predominant cell type within the follicle, GCs not only regulate their own proliferation but also contribute to follicle development by synthesizing hormones (E 2 , P 4 ) ( 5 , 6 ) and growth factors ( 7 , 8 ). The process begins with the transformation of cholesterol, during which the STAR protein plays a pivotal role in translocating cholesterol to the inner mitochondrial membrane.…”

Mutations in NLRP5 and NLRP9 Are Associated with Litter Size in Small Tail Han Sheep

“…Ongoing research has revealed some potential mechanisms underlying this association. GDF9 was reported to enhance mitochondrial activity, meiotic resumption, and secondary follicle development in sheep [25], and GDF9 was also shown to enhance granulosa cell proliferation [26]. Further study indicated that GDF9 is required for normal folliculogenesis in many mammal species [17]; therefore, GDF9 may be a direct factor that influences litter size in ewes by affecting functions of granulosa cells and folliculogenesis.…”