Effect of Different Fruiting Treatments on the Enzymic Activity of Tricholoma giganteum Mycelia

In order to achieve the transformation from the conventional soil-covering cultivation of Tricholoma giganteum with bags to the soilless cultivation with bottles and understand the mechanism of primordium formation of Tricholoma giganteum,with Tricholoma giganteum mycelia as experimental materials,this paper studied the effect of different fruiting treatments on the activity of three enzymes in different time.The results showed that from the mycelial recovery to primardial formation and budding under three treatment groups which could form primordium,the tyrosinase activity was relatively stable,and under two treatment groups which could not form primordium,the tyrosinase activity dropped after the rise and reached a maximum on the 9 th day,significantly higher than under the other three groups,indicating that too high tyrosinase inhibited primardial formation; the prolease and amylase activity was effectively activated before primardial formation,and the enzymic activity was significantly higher than under the two treatment groups which could not form primordium.

SP1 governs primordial folliculogenesis by regulating pregranulosa cell development in mice

Establishment of the primordial follicle(PF)pool is pivotal for the female reproductive lifespan;however,the mechanism of primordial folliculogenesis is poorly understood.Here,the transcription factor SP1 was shown to be essential for PF formation in mice.Our results showed that SP1 is present in both oocytes and somatic cells during PF formation in the ovary.Knockdown of Sp1 expression,especially in pregranulosa cells,significantly suppressed nest breakdown,oocyte apoptosis,and PF formation,suggesting that SP1 expressed by somatic cells functions in the process of primordial folliculogenesis.We further demonstrated that SP1 governs the recruitment and maintenance of Forkhead box L2-positive(FOXL2^+)pregranulosa cells using an Lgr5-EGFP-IRES-CreER^T2(Lgr5-KI)reporter mouse model and a FOXL2^+ cell-specific knockdown model.At the molecular level,SP1 functioned mainly through manipulation of NOTCH2 expression by binding directly to the promoter of the Notch2 gene.Finally,consistent with the critical role of granulosa cells in follicle survival in vitro,massive loss of oocytes in SP1 knockdown ovaries was evidenced before puberty after the ovaries were tranSP1anted under the renal capsules.Conclusively,our results reveal that SP1 controls the establishment of the ovarian reserve by regulating pregranulosa cell development in the mammalian ovary.

The programmed death of fetal oocytes and the correlated surveillance mechanisms

Gamete production is essential for mammalian reproduction.In the ovaries,the primordial follicle,which is the basic reproductive unit,is formed either perinatally or during the second pregnancy stage in humans.However,some oocytes die before the establishment of the primordial follicle pool.Consequently,it is essential to uncover how the size of the primordial follicle pool is determined and how the programmed cell death of oocytes is performed under potential surveillance.According to recent studies,the fate of oocytes in the fetal ovary seems to be determined by different protective strategies through the timely control of apoptosis or autophagy.In this review,we discuss at least three oocyte-derived protective biomarkers,glycogen synthase kinase 3 beta,X-linked inhibitor of apoptosis,and Lysine-specific demethylase 1(also known as KDM1A),responsible for surveilling the developmental quality of fetal oocytes to coordinate primordial follicle formation in the fetal ovary.This review contributes to a better understanding of the secrets of the female reproductive reserve under physiological conditions.