Preliminary Study On The Mechanisms Underlining Male Sterility Of Hybrids Between Sika Deer (Cervus Nippon) And Red Deer (Cervus Elaphus)

Both sika deer and red deer are important special economic animals in China,The offspring of sika deer and red deer crossbreed have heterosis and play an important role in the deer breeding industry.The hybrids offspring of sika deer and red deer usually have reproductive ability.However,in recent years,there are many male deer of some hybrid F1 generation have been found to have the symptoms of oligozoospermia,spermatozoa or sperm malformation in some areas.In response to this phenomenon,F1 male infertility was cultivated in some of the deer farms in Jilin Province and Liaoning Province.Investigations were conducted and attempts were made to explore the causes of these deer infertility through observations of sperm cells,levels of reproductive hormones,karyotype analysis,and related gene expression related to spermatogenesis.The contents of the study are as follows:1.Using a combination of fine needle aspiration cytology and testicular volume measurement to investigate whether or not fertile breeders of deer and red deer F1 hybrids were fertile,we found that a smaller proportion of the male stags were infertile.The stagnation of male stag spermatozoa is different,indicating that the reason for these male stag infertility may not be one.2.We found the level of serum testosterone,estradiol,progesterone,prolactin,luteinizing hormone and prolactin in the normal reproductive stag within the horizontal range through the determination of reproductive hormones in F1 generation male reproductive period.The reason of these stags are infertile is not related to reproductive endocrinology.3.After chromosomal spreading,it can be seen that there are 33 or 34 chromosomes in the male deer of the F1 hybrid of the deer and red deer.One or two of them are intermediate centromere chromosomes,and the X chromosome is the longest chromosome.Chromosomes are the shortest chromosomes.Comparisons of male infertility individuals with those of normal individuals do not reveal morphological aberrations and quantitative abnormalities.4.EDEM,SO9,UBE2J1 and MSFD14 A are involved in the transformation of round spermatids into long spermatids in the process of spermatogenesis.CREM is a regulatory element that regulates the differentiation of spermatogonial stem cells.Real-time fluorescence quantification techniques are used to analyze normal hybrids.The hybrid deer found that the mRNA expression of EDEM,SO9,CREM and MSFD14 A in the sterile deer had a different degree of up-regulation than that of the normal deer,and the expression of UBE2J1 was down-regulated.This indicates that male infertility in deer hybridization is related to EDEM,SO9,CREM and MSFD14 A.