Pericellular and extracellular proteoglycans play an important role in modulating morphogen gradients and signal transductions. Chondroitin sulfate proteoglycan 4 (Cspg4) is a membrane spanning proteoglycan expressed in immature progenitor cells and cancer cells. Cspg4 participates in cellular events such as proliferation, migration and signal transduction, and these events are generally important for embryo development. In this study, we characterized Cspg4 for its roles in zebrafish embryonic development. Our results demonstrated that cspg4 was maternally expressed from 0 to 3 hours post fertilization (hpf) and expressed in the anterior and posterior embryo end after 9 hpf. Knocking-down cspg4 resulted in a shorter anterior-posterior axis than control embryo, which could be rescued by co-injecting wnt11 mRNA suggesting that Cspg4 regulates body axis organization through modulating the Wnt/planar cell polarity signaling pathway. In addition, overexpressing cspg4 caused cyclopia. The Cspg4 transmembrane domain mutant embryo phenocopied the global over-expression of cspg4 mRNA and led to cyclopia with a very low penetrance. Our results demonstrated that the quantitatively and spatially accurate distribution of Cspg4 is critical for body axis and midline development during gastrulation.

Global warming has a significant impact on the dairy farming industry, as heat stress causes reproductive endocrine imbalances and leads to substantial economic losses, particularly in tropical–subtropical regions. The Holstein breed, which is widely used for dairy production, is highly susceptible to heat stress, resulting in a dramatic reduction in milk production during hot seasons. However, previous studies have shown that cells of cows produced from reconstructed embryos containing cytoplasm (o) from Taiwan yellow cattle (Y) have improved thermotolerance despite their nuclei (n) being derived from heat-sensitive Holstein cattle (H). Using spindle transfer (ST) technology, we successfully produced ST-Yo-Hn cattle and proved that the thermotolerance of their ear fibroblasts is similar to that of Y and significantly better than that of H (p < 0.05). Despite these findings, the genes and molecules responsible for the different sensitivities of cells derived from ST-Yo-Hn and H cattle have not been extensively investigated. In the present study, ear fibroblasts from ST-Yo-Hn and H cattle were isolated, and differentially expressed protein and gene profiles were compared with or without heat stress (hs) (42 °C for 12 h). The results revealed that the relative protein expression levels of pro-apoptotic factors, including Caspase-3, -8, and -9, in the ear fibroblasts from the ST-Yo-Hn-hs group were significantly lower (p < 0.05) than those from the H-hs group. Conversely, the relative expression levels of anti-apoptotic factors, including GNA14 protein and the CRELD2 and PRKCQ genes, were significantly higher (p < 0.05) in the ear fibroblasts from the ST-Yo-Hn-hs group compared to those from the H-hs group. Analysis of oxidative phosphorylation-related factors revealed that the relative expression levels of the GPX1 gene and Complex-I, Complex-IV, CAT, and PGLS proteins were significantly higher (p < 0.05) in the ear fibroblasts from the ST-Yo-Hn-hs group compared to those from the H-hs group. Taken together, these findings suggest that ear fibroblasts from ST-Yo-Hn cattle have superior thermotolerance compared to those from H cattle due to their lower expression of pro-apoptotic factors and higher expression of oxidative phosphorylation and antioxidant factors. Moreover, this improved thermotolerance is attributed, at least partially, to the cytoplasm derived from more heat-tolerant Y cattle. Hence, using ST technology to produce more heat-tolerant H cattle containing Y cytoplasm could be a feasible approach to alleviate the negative impacts of heat stress on dairy cattle in tropical–subtropical regions.

This study investigated whether maternal origin affects boar semen thermotolerance and its seasonal reproductive performance. Crossbred boars with different maternal origins were evaluated (K and KD boars with Meishan-derived cytoplasm and DK boars with Duroc-derived cytoplasm). Heat stress treatment (42 and 39 °C) on semen samples significantly reduced sperm viability and acrosome/membrane integrity while increasing mitochondrial damage. Notably, the decline in semen quality under heat stress was significantly lower (p < 0.05) in K and KD boars than in DK boars. The farrowing rates during the hot season were significantly higher (p < 0.05) in the K and KD breed compared with the DK breed. No significant differences among groups were observed during the cool season. Collectively, these findings indicate that maternal origin may contribute to mitochondrial stability and semen resilience under tropical heat stress, thereby influencing reproductive performance in hot seasons. Maternal inheritance should therefore be considered in breeding strategies of improving heat tolerance in pigs.