Diploid hybrid fish derived from the cross between female Bleeker’s yellow tail and male topmouth culter, two cyprinid fishes belonging to different subfamilies

Abstract

BackgroundBleeker’s yellow tail (Xenocypris davidi Bleeker, YT) and topmouth culter (Culter alburnus Basilewsky, TC) are both famous and important economic freshwater fish in China. YT, a kind of omnivorous fish, has strong resistance. TC, a kind of carnivorous fish, has high-quality meat but poor resistance. Distant hybridization can integrate the advantages of both parents. There has been no previous report regarding hybrid fish derived from female YT × male TC. It is expected that hybridization of these two kinds of fish will result in F1 hybrids with improved characteristics, such as faster growth rate, stronger resistance, and high-quality meat, which are of great significance in fish genetic breeding.ResultsIn this study, we investigated the main biological characteristics of diploid hybrid fish derived from female YT × male TC. The hybrids had an intermediate number of upper lateral line scales between those for YT and TC. The hybrids were diploids with 48 chromosomes and had the same karyotype formula as their parents. The hybrids generated variations in 5S rDNA (designated class IV: 212 bp) and lost specific 5S rDNA derived from the maternal parent (designated class II: 221 bp), which might be related to hybridization. In terms of reproductive traits, all the tested female hybrids exhibited normal gonadal development, and the two-year-old F1 females produced mature eggs. However, all the tested testes of the male hybrids could not produce mature sperm. It is possible that the hybrid lineage will be established by back-crossing the fertile female hybrids and their parents.ConclusionsObtaining a fertile female hybrid fish made the creation of a new type of fish possible, which was significant in fish genetic breeding.

Genetic Diversity Evaluation of Two Loach Fishes and their Artificial Hybrid Population Based on 19 Polymorphic Microsatellite Loci

“…Previous researches reported that distant hybridization was an important evolutionary mechanism of breeding, which could combine the excellent traits of the parents, increase genetic diversity, obtain excellent new hybrid varieties, increase the fitness and adaptive potential of populations (Lou and Li, 2006;Szűcs et al, 2012). Distant hybridization has been widely used in the genetic breeding of fish such as Megalobrama amblycephala (Qin et al, 2018), Erythroculter ilishaeformis (Li et al, 2019), Epinephelus fuscoguttatus (Chen et al, 2018), and Siniperca scherzeri (Shan et al, 2013), and a certain level of hybrid vigor was detected. Thus, we speculated that the hybridization of S. superciliaris and S. reevesae may help compensate for the small testis and low sperm of the mature male of S. superciliaris, thereby expanding the industrialization and the preservation of germplasm resources of these two loaches.…”

Developmental potential of somatic and germ cells of hybrids betweenCarassius auratusfemales andHemigrammocypris rasborellamales

“…In cyprinid species, many hybrids have been produced via interspecies, inter-genus, and even inter-family combinations (Suzuki, 1956(Suzuki, , 1961(Suzuki, , 1962(Suzuki, , 1968Ojima, 1973). For inter-subfamilial hybrids that have been produced using species from the subfamilies Acheilognathinae, Gobioninae or Cyprininae, most of these progeny exhibited inviability at the hatching stage (Suzuki, 1956(Suzuki, , 1961(Suzuki, , 1962(Suzuki, , 1968, while those between species in Oxygastrinae exceptionally developed normally and produced mature eggs (Li et al, 2019). Although inviable cyprinid hybrids have not been cytogenetically studied, Kijima and colleagues (1996a,b) reported that inviable interfamilial hybrids between dojo loach females (family Cobitidae) and goldfish, minnow or common carp males (family Cyprinidae), had allo-diploid karyotypes intermediate between the two parental species.…”