[Synaptonemal complex: the fundamental structure of meiosis].

Meiosis is a special type of cell division to produce haploid gametes with intact genome. The behavior of homologous chromosomes during the first division (meiosis prophase I) is the most prominent feature of meiosis. During meiosis prophase I, synaptonemal complex (SC) formed between homologous chromosomes to promote the initiation and repair of programmed DNA double-strand breaks (DSBs), which is necessary for the correct recognition, pairing, recombination and separation of homologous chromosomes. In this paper, we reviewed the recent research progress on the composition and function of SC, discussed how the assembly of SC affected the repair of DSBs, and also summarized the known mutations on SC genes which were responsible for human reproductive disorders. On this basis, we also explored the future research direction of this field.

CCDC181 is required for sperm flagellum biogenesis and male fertility in mice.

The structural integrity of the sperm flagellum is essential for proper sperm function. Flagellar defects can result in male infertility, yet the precise mechanisms underlying this relationship are not fully understood. CCDC181, a coiled-coil domain-containing protein, is known to localize on sperm flagella and at the basal regions of motile cilia. Despite this knowledge, the specific functions of CCDC181 in flagellum biogenesis remain unclear. In this study, Ccdc181 knockout mice were generated. The absence of CCDC181 led to defective sperm head shaping and flagellum formation. Furthermore, the Ccdc181 knockout mice exhibited extremely low sperm counts, grossly aberrant sperm morphologies, markedly diminished sperm motility, and typical multiple morphological abnormalities of the flagella (MMAF). Additionally, an interaction between CCDC181 and the MMAF-related protein LRRC46 was identified, with CCDC181 regulating the localization of LRRC46 within sperm flagella. These findings suggest that CCDC181 plays a crucial role in both manchette formation and sperm flagellum biogenesis.

Homozygous CCDC146 mutation causes oligoasthenoteratozoospermia in humans and mice.

Infertility represents a significant health concern, with sperm quantity and quality being crucial determinants of male fertility. Oligoasthenoteratozoospermia (OAT) is characterized by reduced sperm motility, lower sperm concentration, and morphological abnormalities in sperm heads and flagella. Although variants in several genes have been implicated in OAT, its genetic etiologies and pathogenetic mechanisms remain inadequately understood. In this study, we identified a homozygous nonsense mutation (c.916C>T, p.Arg306*) in the coiled-coil domain containing 146 ( CCDC146) gene in an infertile male patient with OAT. This mutation resulted in the production of a truncated CCDC146 protein (amino acids 1-305), retaining only two out of five coiled-coil domains. To validate the pathogenicity of the CCDC146 mutation, we generated a mouse model ( Ccdc146 mut/mut ) with a similar mutation to that of the patient. Consistently, the Ccdc146 mut/mut mice exhibited infertility, characterized by significantly reduced sperm counts, diminished motility, and multiple defects in sperm heads and flagella. Furthermore, the levels of axonemal proteins, including DNAH17, DNAH1, and SPAG6, were significantly reduced in the sperm of Ccdc146 mut/mut mice. Additionally, both human and mouse CCDC146 interacted with intraflagellar transport protein 20 (IFT20), but this interaction was lost in the mutated versions, leading to the degradation of IFT20. This study identified a novel deleterious homozygous nonsense mutation in CCDC146 that causes male infertility, potentially by disrupting axonemal protein transportation. These findings offer valuable insights for genetic counseling and understanding the mechanisms underlying CCDC146 mutant-associated infertility in human males.

[Effects of Long Non-coding RNA-TUC338 on the Migration and Proliferation of Lymphoma Cells via PI3K/AKT Signaling Pathway].

OBJECTIVE: To investigate the effect of long non-coding RNA-TUC338 on the proliferation and migration of lymphoma cells. METHODS: The expression of TUC338 in different lymphoma cells was detected by fluorescence quantitative PCR, cell proliferation by sulforhodamine B (SRB) assay, migration of lymphoma cells by transwell assay, and protein expression in PI3K/AKT signaling pathway by Western blot. RESULTS: The expression levels of TUC338 in lymphoma cells Daudi, U937, BC-3, and Raji significantly increased in comparison with human normal T lymphocytes H9 (t=13.277, 10.103, 16.200, and 26.687, P=0.002, 0.005, 0.001, and 0.000). Compared with NC-siRNA group, the number of cells crossing the chamber of TUC338-siRNA group was significantly reduced (t=30.508, P=0.000), the protein expression levels of p-PI3K and p-AKT significantly decreased (t=16.872 and 18.371, P=0.000 and 0.000), and OD530 absorbance values at 24 h, 48 h, and 72 h were significantly lower (P<0.05). CONCLUSION: The expression of TUC338 significantly increases in lymphoma cells, and silence of TUC338 effectively inhibits the activation of PI3K/AKT signaling pathway, thereby inhibiting the proliferation and migration of lymphoma cells, which has a potential application value in diagnosis and treatment of lymphoma.

[Relationship of Expression of Circ_cgga162 with the Prognosis of Patients with Mantle Cell Lymphoma].

OBJECTIVE: To investigate the expression of Circ_cgga162 in serum of mantle cell lymphoma (MCL) patients and analyze its potential as a prognostic biomarker. METHODS: The expression of Circ_cgga162 in 86 cases of mantle cell lymphoma and 50 cases of lymph node reactive hyperplasia (RH) were detected by real-time quantitative polymerase chain reaction (qRT-PCR). The relationship between the expression of Circ_cgga162 and clinicopathological features was analyzed by univariate analysis. The relationship of Circ_cgga162 expression with progression-free survival time and overall survival time was analyzed by Kaplan-Meier. The relationship between expression of Circ_cgga162 and prognosis of patients was analyzed by univariate and multivariate analysis. RESULTS: The expression level of Circ_cgga162 in MCL patients was significantly higher than that in control (RH) group (P＜0.01). The expression of Circ_cgga162 not correlated with age, gender, B symptoms and LDH (all P＞0.05), but correlated with the expression of MCL International Prognostic Index (IPI), Ann Arbor stage, bone marrow infiltration and Ki67 (all P＜0.05). In addition, Kaplan-Meier analysis showed that the progression-free survival time and overall survival time of the MCL patients with high expression of Circ_cgga162 were significantly shorter than those of the MCL patients with low expression (P＜0.01). Univariate analysis showed that Ann Arbor stage, Circ_cgga162 expression, MIPI, bone marrow infiltration and Ki67 were the prognostic factors for MCL patients (all P＜0.05). Multivariate Cox regression analysis showed that Ann Arbor stage, Circ_cgga162 expression and MIPI were independent factors affecting the prognosis of MCL patients (all P＜0.05). CONCLUSION: Circ_cgga162 is highly expressed in serum of patients MCL, which relates with the prognosis of MCL patients. Circ_cgga162 can be used as a potential prognostic marker and therapeutic target for MCL patients.