Transcriptomic Analysis of the Developing Testis and Spermatogenesis in Qianbei Ma Goats

Reproductive competence in male mammals depends on testicular function. Testicular development and spermatogenesis in goats involve highly complex physiological processes. In this study, six testes were, respectively, obtained from each age group, immature (1 month), sexually mature (6 months) and physically mature (12 months old) Qianbei Ma goats. RNA-Seq was performed to assess testicular mRNA expression in Qianbei Ma goats at different developmental stages. Totally, 18 libraries were constructed to screen genes and pathways involved in testis development and spermatogenesis. Totally, 9724 upregulated and 4153 downregulated DEGs were found between immature (I) and sexually mature (S) samples; 7 upregulated and 3 downregulated DEGs were found between sexually mature (S) and physically mature (P) samples, and about 4% of the DEGs underwent alternative splicing events between I and S. Select genes were assessed by qRT-PCR, corroborating RNA-Seq findings. The detected genes have key roles in multiple developmental stages of goat testicular development and spermatogenesis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to determine differentially expressed genes (DEGs). GO analysis revealed DEGs between S and P contributed to "reproduction process", "channel activity" and "cell periphery part" between I and S, and in "ion transport process", "channel activity" and "transporter complex part". KEGG analysis suggested the involvement of "glycerolipid metabolism", "steroid hormone biosynthesis" and "MAPK signaling pathway" in testis development and spermatogenesis. Genes including IGF1, TGFB1, TGFBR1 and EGFR may control the development of the testis from immature to sexually mature, which might be important candidate genes for the development of goat testis. The current study provides novel insights into goat testicular development and spermatogenesis.

FOXP3 pathogenic variants cause male infertility through affecting the proliferation and apoptosis of human spermatogonial stem cells

Genetic causes of male infertility that is associated with aging are largely unknown. This study was designed to identify novel pathogenic variants of FOXP3 gene causing azoospermia. One homozygous (c.155 G > T) pathogenic variant of FOXP3 was identified in nine non-obstructive azoospermia patients, and one heterozygous (c.691 C > A) of FOXP3 was found in one non-obstructive azoospermia patient. Pedigrees studies indicated that the homozygous (c.155 G > T) FOXP3 pathogenic variant was inherited, while heterozygous (c.691 C > A) FOXP3 pathogenic variant was acquired. Human testis carrying pathogenic variant exhibited abnormal spermatogenesis. FOXP3 protein was expressed at a lower level or undetected in spermatocytes of mutant testis of non-obstructive azoospermia patients compared to obstructive azoospermia patients. FOXP3 stimulated the proliferation and inhibited the apoptosis of human spermatogonial stem cells, and we further analyzed the targets of FOXP3. We have identified two new pathogenic variants of FOXP3 in non-obstructive azoospermia patients with high incidence, and FOXP3 silencing inhibits the proliferation and enhances the apoptosis of human spermatogonial stem cells. This study provides new insights into the etiology of azoospermia and offers novel pathogenic variants for gene targeting of male infertility.

Cytokine networks that mediate epithelial cell-macrophage crosstalk in the mammary gland: implications for development and cancer

Dynamic interactions between the hormone responsive mammary gland epithelium and surrounding stromal macrophage populations are critical for normal development and function of the mammary gland. Macrophages are versatile cells capable of diverse roles in mammary gland development and maintenance of homeostasis, and their function is highly dependent on signals within the local cytokine microenvironment. The mammary epithelium secretes a number of cytokines, including colony stimulating factor 1 (CSF1), transforming growth factor beta 1 (TGFB1), and chemokine ligand 2 (CCL2) that affect the abundance, phenotype and function of macrophages. However, aberrations in these interactions have been found to increase the risk of tumour formation, and utilisation of stromal macrophage support by tumours can increase the invasive and metastatic potential of the cancer. Studies utilising genetically modified mouse models have shed light on the significance of epithelial cell-macrophage crosstalk, and the cytokines that mediate this communication, in mammary gland development and tumourigenesis. This article reviews the current status of our understanding of the roles of epithelial cell-derived cytokines in mammary gland development and cancer, with a focus on the crosstalk between epithelial cells and the local macrophage population.

The essential roles of TGFB1 in reproduction

Transforming growth factor beta 1 (TGFB1) is implicated as a key regulator of the development and cyclic remodelling characteristic of reproductive tissues. The physiological significance of TGFB1 in reproductive biology and fertility has been extensively examined in Tgfb1 null mutant mice. Genetic deficiency in TGFB1 causes perturbed functioning of the hypothalamic-pituitary-gonadal axis, inhibiting luteinising hormone (LH) synthesis and leading to downstream effects on testosterone production in males and estrous cycle abnormalities in females. Oocyte developmental incompetence, accompanied by early embryo arrest as well as altered pubertal mammary gland morphogenesis are observed. In addition to LH and testosterone deficiency, male Tgfb1 null mice demonstrate complete inability to mate with females, associated with failure to initiate and/or sustain successful penile intromission or ejaculation. These studies demonstrate the profound significance of TGFB1 in male and female reproductive physiology, and provide a foundation for exploring the significance of this cytokine in human infertility and sexual dysfunction.