FSIP2 plays a role in the acrosome development during spermiogenesis

Exploring the genetic control of sweat gland characteristics in beef cattle for enhanced heat tolerance

BACKGROUND

Thermal stress in subtropical regions is a major limiting factor in beef cattle production systems with around $369 million being lost annually due to reduced performance. Heat stress causes numerous physiological and behavioral disturbances including reduced feed intake and decreased production levels. Cattle utilize various physiological mechanisms such as sweating to regulate internal heat. Variation in these traits can help identify genetic variants that control sweat gland properties and subsequently allow for genetic selection of cattle with greater thermotolerance.

METHODS

This study used 2,401 Brangus cattle from two commercial ranches in Florida. Precise phenotypes that contribute to an animal's ability to manage heat stress were calculated from skin biopsies and included sweat gland area, sweat gland depth, and sweat gland length. All animals were genotyped with the Bovine GGP F250K, and BLUPF90 software was used to estimate genetic parameters and for Genome Wide Association Study.

RESULTS

Sweat gland phenotypes heritability ranged from 0.17 to 0.42 indicating a moderate amount of the phenotypic variation is due to genetics, allowing producers the ability to select for favorable sweat gland properties. A weighted single-step GWAS using sliding 10 kb windows identified multiple quantitative trait loci (QTLs) explaining a significant amount of genetic variation. QTLs located on BTA7 and BTA12 explained over 1.0% of genetic variance and overlap the ADGRV1 and CCDC168 genes, respectively. The variants identified in this study are implicated in processes related to immune function and cellular proliferation which could be relevant to heat management. Breed of Origin Alleles (BOA) were predicted using local ancestry in admixed populations (LAMP-LD), allowing for identification of markers' origin from either Brahman or Angus ancestry. A BOA GWAS was performed to identify regions inherited from particular ancestral breeds that might have a significant impact on sweat gland phenotypes.

CONCLUSIONS

The results of the BOA GWAS indicate that both Brahman and Angus alleles contribute positively to sweat gland traits, as evidenced by favorable marker effects observed from both genetic backgrounds. Understanding and utilizing genetic traits that confer better heat tolerance is a proactive approach to managing the impacts of climate change on livestock farming.

Coiled-coil domain-containing 38 is required for acrosome biogenesis and fibrous sheath assembly in mice

During spermiogenesis, haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes, which are required for successful fertilization. Severe deformities in flagella cause a male infertility syndrome, multiple morphological abnormalities of the flagella (MMAF), while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential. However, evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited. Here, we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38 (Ccdc38) via inducing a nonsense mutation and find that the males are infertile. The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes. We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm. Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3, a protein associated with acrosome biogenesis, in testes and an aberrant distribution of TEKT3 in sperm. We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility. Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.

Dopamine receptor D2 regulates genes involved in germ cell movement and sperm motility in rat testes†

The function of dopamine receptor D2 (D2R) is well associated with sperm motility; however, the physiological role of D2R present on testicular cells remains elusive. The aim of the present study is to delineate the function of testicular D2R. Serum dopamine levels were found to decrease with age, whereas testicular D2R expression increased. In rat testicular sections, D2R immunolabeling was observed in interstitial cells, spermatogonia, spermatocytes and mature elongated spermatids, whereas tyrosine hydroxylase immunolabeling was selectively detected in Leydig cells. In vitro seminiferous tubule culture following bromocriptine (D2R agonist) treatment resulted in decreased cAMP levels. Microarray identified 1077 differentially expressed genes (511 up-regulated, 566 down-regulated). The majority of differentially expressed genes were present in post-meiotic cells including early and late spermatids, and sperm. Gene ontology elucidated processes related to extra-cellular matrix to be enriched and was supported by differential expression of various collagens and laminins, thereby indicating a role of dopamine in extra-cellular matrix integrity and transport of spermatids across the seminiferous epithelium. Gene ontology and enrichment map also highlighted cell/sperm motility to be significantly enriched. Therefore, genes involved in sperm motility functions were further validated by RT-qPCR. Seven genes (Akap4, Ccnyl1, Iqcf1, Klc3, Prss55, Tbc1d21, Tl18) were significantly up-regulated, whereas four genes (Dnah1, Dnah5, Clxn, Fsip2) were significantly down-regulated by bromocriptine treatment. The bromocriptine-stimulated reduction in seminiferous tubule cyclic AMP and associated changes in spermatid gene expression suggests that dopamine regulates both spermatogenesis and spermiogenesis within the seminiferous epithelium, and spermatozoa motility following spermiation, as essential processes for fertility.

Comprehensive analyses of 435 goat transcriptomes provides insight into male reproduction

A systematic analysis of genes related to reproduction is crucial for obtaining a comprehensive understanding of the molecular mechanisms that underlie male reproductive traits in mammals. Here, we utilized 435 goat transcriptome datasets to unveil the testicular tissue-specific genes (TSGs), allele-specific expression (ASE) genes and their uncharacterized transcriptional features related to male goat reproduction. Results showed a total of 1790 TSGs were identified in goat testis, which was the most among all tissues. GO enrichment analyses suggested that testicular TSGs were mainly involved in spermatogenesis, multicellular organism development, spermatid development, and flagellated sperm motility. Subsequently, a total of 95 highly conserved TSGs (HCTSGs), 508 middle conserved TSGs (MCTSGs) and 42 no conserved TSGs (NCTSGs) were identified in goat testis. GO enrichment analyses suggested that the HCTSGs and MCTSGs has a more important association with male reproduction than NCTSGs. Additionally, we identified 644 ASE genes, including 88 tissue-specific ASE (TS-ASE) genes (e.g., FSIP2, TDRD9). GO enrichment analyses indicated that both ASE genes and TS-ASE genes were associated with goat male reproduction. Overall, this study revealed an extensive gene set involved in the regulation of male goat reproduction and their dynamic transcription patterns. Data reported here provide valuable insights for a further improvement of the economic benefits of goats as well as future treatments for male infertility.

Protein Kinase CK2α', More than a Backup of CK2α

The serine/threonine protein kinase CK2 is implicated in the regulation of fundamental processes in eukaryotic cells. CK2 consists of two catalytic α or α' isoforms and two regulatory CK2β subunits. These three proteins exist in a free form, bound to other cellular proteins, as tetrameric holoenzymes composed of CK2α2/β2, CK2αα'/β2, or CK2α'2/β2 as well as in higher molecular forms of the tetramers. The catalytic domains of CK2α and CK2α' share a 90% identity. As CK2α contains a unique C-terminal sequence. Both proteins function as protein kinases. These properties raised the question of whether both isoforms are just backups of each other or whether they are regulated differently and may then function in an isoform-specific manner. The present review provides observations that the regulation of both CK2α isoforms is partly different concerning the subcellular localization, post-translational modifications, and aggregation. Up to now, there are only a few isoform-specific cellular binding partners. The expression of both CK2α isoforms seems to vary in different cell lines, in tissues, in the cell cycle, and with differentiation. There are different reports about the expression and the functions of the CK2α isoforms in tumor cells and tissues. In many cases, a cell-type-specific expression and function is known, which raises the question about cell-specific regulators of both isoforms. Another future challenge is the identification or design of CK2α'-specific inhibitors.

A novel mutation in CFAP47 causes male infertility due to multiple morphological abnormalities of the sperm flagella

Introduction

A previous study suggested that loss of CFAP47 function is involved in multiple morphological abnormalities of the sperm flagella (MMAF) in humans and mice. However, the comprehensive role of CFAP47 in spermatogenesis is largely unknown.

Methods

Whole-exome sequencing (WES) was conducted to identify pathogenic variant in two patients with MMAF. The functional effect of the identified mutations was investigated by immunofluorescence staining and western blotting. Intracytoplasmic sperm injection (ICSI) was used to assist fertilization for the patient with MMAF.

Results

In this study, we identified a novel missense mutation (c.1414G>A; p.V472M) in CFAP47 in two unrelated patients with oligoasthenoteratozoospermia. Intriguingly, in addition to the MMAF phenotype very analogous to the previous report, the two patients notably presented abnormal morphology of sperm heads, the sperm mitochondrial sheath was obviously disorganized, and the sperm annulus were almost defective. Further functional experiments confirmed that the expression of CFAP47 was markedly reduced in the spermatozoa of the patients. Mechanism analysis suggested that CFAP47 might regulate the expression of CFAP65, CFAP69 and SEPTIN4 through their physical interactions and thus modulating sperm morphogenesis.

Conclusion

we revealed a novel mutation in CFAP47 and further expanded the phenotype and mutation spectrum of CFAP47, as well as the potential mechanism of CFAP47 manipulating spermatogenesis, finally providing important guidance for genetic counseling and targeted treatment for CFAP47 mutation-related male infertility.

Compound Heterozygous Mutations in FSIP2 Cause Morphological Abnormalities in Sperm Flagella Leading to Male Infertility

Multiple morphological abnormalities of sperm flagella (MMAF) indicate severe teratozoospermia. The fibrous sheath interacting protein 2 (FSIP2) plays an important role in the normal construction of the flagella. In this study, a novel compound heterozygous mutation site of FSIP2, involving c.272_275delinsAGGTTTTTATA (p.L92Vfster74) and c.16788_16791del (p.E5596fs), was identified using whole-exome sequencing in a 32-year-old male. Electron microscope images revealed thick sperm neck, scattered sperm mitochondria, and short sperm tail. In addition, FSIP2 could not be visualized in sperm cells via immunofluorescence staining. Moreover, we used a protein domain prediction tool to identify a potential FSIP2 functional domain (5901-6774), the corresponding deletion of which was responsible for the MMAF phenotype in the infertile man. Finally, we reviewed the literature on FSIP2 and found that FSIP2 mutations are relatively concentrated, with high-frequency mutation regions in exon 16 and exon 17 accounting for 50% (10/20) and 35% (7/20) of cases, respectively. In conclusion, FISP2 is a common pathogenic gene of MMAF, which may provide a rationale for genetic counseling in the next generation of patients with male infertility.

Clinical detection, diagnosis and treatment of morphological abnormalities of sperm flagella: A review of literature

Sperm carries male genetic information, and flagella help move the sperm to reach oocytes. When the ultrastructure of the flagella is abnormal, the sperm is unable to reach the oocyte and achieve insemination. Multiple morphological abnormalities of sperm flagella (MMAF) is a relatively rare idiopathic condition that is mainly characterized by multiple defects in sperm flagella. In the last decade, with the development of high-throughput DNA sequencing approaches, many genes have been revealed to be related to MMAF. However, the differences in sperm phenotypes and reproductive outcomes in many cases are attributed to different pathogenic genes or different pathogenic mutations in the same gene. Here, we will review information about the various phenotypes resulting from different pathogenic genes, including sperm ultrastructure and encoding proteins with their location and functions as well as assisted reproductive technology (ART) outcomes. We will share our clinical detection and diagnosis experience to provide additional clinical views and broaden the understanding of this disease.