Chromosome-scale and haplotype-resolved genome assembly of the autotetraploid Misgurnus anguillicaudatus.

In nature, diploids and tetraploids are two common types of polyploid evolution. Misgurnus anguillicaudatus (mud loach) is a remarkable fish species that exhibits both diploid and tetraploid forms. However, reconstructing the four haplotypes of its autotetraploid genome remains unresolved.

Morpho-histological and Transcriptome Analysis Reveal the Unreduced Sperm Formation Mechanism in cdk1-Depletion Zebrafish.

Cyclin-dependent kinases (Cdks) are major molecules related to cell cycle regulation. Polyploidy can be caused by the production of unreduced gametes, which is often related to the abnormal cell cycle of germ cells. Here, we successfully constructed a cdk1 mutation line (cdk1) in zebrafish, a commonly used model organism.

Mitotic defects lead to unreduced sperm formation in cdk1 mutants.

Unreduced gametes, that are important for species evolution and agricultural development, are generally believed to be formed by meiotic defects. However, we found that male diploid loach (Misgurnus anguillicaudatus) could produce not only haploid sperms, but also unreduced sperms, after cyclin-dependent kinase 1 gene (cdk1, one of the most important kinases in regulating cell mitosis) deletion. Observations on synaptonemal complexes of spermatocyte in prophase of meiosis and spermatogonia suggested that the number of chromosomes in some spermatogonia of cdk1 loach doubled, leading to unreduced diploid sperm production.

Depletion of chop suppresses procedural apoptosis and enhances innate immunity in loach Misgurnus anguillicaudatus under ammonia nitrogen stress.

Ammonia nitrogen is highly toxic to fish, and it can easily cause fish poisoning or even high mortality. So far, many studies have been conducted on the damages to fish under ammonia nitrogen stress. However, there are few studies of ammonia tolerance improvement in fish.

Expression profiles of cdca9 related to ovarian development in loach (Misgurnus anguillicaudatus).

The function of borealin proteins has been widely reported in the cell division of animals. Nonetheless, there is little research about their only known paralogue (cell division cycle associated 9, cdca9). In this study, cdca9 was investigated in loach (Misgurnus anguillicaudatus) for the first time.

De novo gonad transcriptome analysis of elongate loach (Leptobotia elongata) provides novel insights into sex-related genes.

Elongate loach (Leptobotia elongata) is endemic in middle and upper reaches of the Yangtze River in China. Because of many anthropogenic factors such as overfishing and dam construction, the loach has become a highly endangered species. So far, the genomic resources which benefit for species conservation and utilization are still lacking in elongate loach.