CEP128, a centrosomal protein, is integral to the centrosome, a key eukaryotic organelle for reproduction. It localizes to the subdistal appendages of the mother centriole and is involved in regulating ciliary signaling, particularly the TGF-β/BMP signaling pathway [2,3]. It also plays a role in organizing the cellular microtubular network [2]. Genetic models, such as mouse models, have been crucial in understanding its functions.

In male fertility research, homozygous Cep128 knock-out (KO) and knock-in (KI) mice have provided significant insights. Male homozygous KO mice show male infertility due to disrupted sperm quality, while KI mice with the orthologous CEP128R222Q variant display anomalies in sperm morphology, count, and motility. Defective sperm flagella were observed in both KO and KI mice, indicating CEP128's role in male reproduction by regulating gene expression and phosphorylation of TGF-β/BMP-signalling members during spermatogenesis [1].

In conclusion, CEP128 is essential for male fertility, influencing sperm development. The use of KO and KI mouse models has been instrumental in uncovering its role in this biological process, highlighting its importance in reproductive biology.

References:

1. Zhang, Xueguang, Wang, Lingbo, Ma, Yongyi, Yang, Yihong, Shen, Ying. 2022. CEP128 is involved in spermatogenesis in humans and mice. In Nature communications, 13, 1395. doi:10.1038/s41467-022-29109-7. https://pubmed.ncbi.nlm.nih.gov/35296684/

2. Kashihara, Hiroka, Chiba, Shuhei, Kanno, Shin-Ichiro, Yano, Tomoki, Tsukita, Sachiko. 2019. Cep128 associates with Odf2 to form the subdistal appendage of the centriole. In Genes to cells : devoted to molecular & cellular mechanisms, 24, 231-243. doi:10.1111/gtc.12668. https://pubmed.ncbi.nlm.nih.gov/30623524/

3. Mönnich, Maren, Borgeskov, Louise, Breslin, Loretta, Larsen, Lars A, Pedersen, Lotte B. . CEP128 Localizes to the Subdistal Appendages of the Mother Centriole and Regulates TGF-β/BMP Signaling at the Primary Cilium. In Cell reports, 22, 2584-2592. doi:10.1016/j.celrep.2018.02.043. https://pubmed.ncbi.nlm.nih.gov/29514088/