Genetic diversity analysis and development of molecular markers for the identification of largemouth bass (Micropterus salmoides L.) based on whole-genome re-sequencing.

Largemouth bass (Micropterus salmoides L.) is generally considered to comprise two subspecies, Florida bass (M. floridanus) and Northern Largemouth bass (M. salmoides), which have biological characteristic differences because of their geographical distribution. In this study, whole-genome re-sequencing was performed among 10 Florida and 10 Northern largemouth bass, respectively. In total, 999,793 SNPs and 227,797 InDels were finally identified, and 507,401 SNPs (50.75%) and 116,213 InDels (51.01%) were successfully mapped to annotated 18,629 genes and 14,060 genes, respectively. KEGG classification indicated that most of these genes were focused on the pathways including signal transduction, transport and catabolism, and endocrine system. Genetic diversity analysis indicated that Florida largemouth bass had higher genetic diversity than Northern largemouth bass, indicating that the germplasm quality of Northern largemouth bass had markedly reduced in China. To examine the accuracies of the identified markers, 23 SNPs and eight InDels (the insertions or deletions of more than 45 bp) were randomly selected and detected among Florida largemouth bass, Northern largemouth bass, and their F1 hybrids. The detection efficiencies of all the markers were higher than 95%; nineteen SNPs and three InDels could accurately distinguish the two subspecies and their F1 hybrids with 100% efficiencies. Moreover, the three InDel markers could clearly distinguish the two subspecies and their F1 hybrids with a PCR-based agarose gel electrophoresis. In conclusion, our study established a simple PCR-based method for the germplasm identification of largemouth bass, which will be useful in the germplasm protection, management, and hybridization breeding of largemouth bass.

Du J ，Li S ，Shao J ，Song H ，Jiang P ，Lei C ，Bai J ，Han L ... -  《Frontiers in Genetics》

The complete mitochondrial genomes of largemouth bass of the northern subspecies (Micropterus salmoides salmoides) and Florida subspecies (Micropterus salmoides floridanus) and their applications in the identification of largemouth bass species.

Li SJ ，Bai JJ ，Cai L ，Ma DM ，Du FF ... -  《-》

Discovery and validation of gene-linked diagnostic SNP markers for assessing hybridization between Largemouth bass (Micropterus salmoides) and Florida bass (M. floridanus).

Efforts to improve recreational fisheries have included widespread stocking of Micropterus floridanus outside its native range of peninsular Florida. Hybridization of Florida bass (M. floridanus) with largemouth bass (Micropterus salmoides) has now dramatically expanded beyond a naturally occurring intergrade zone in the southeast U.S. In recent years, there has been growing interest in protecting the genetic integrity of native basses and assessing the impact and nature of M. salmoides/M. floridanus introgression from the standpoint of hatchery and sport-fishery managers, fish biologists, ecologists and evolutionary biologists. Here, we conducted RNA-seq-based sequencing of the transcriptomes of M. salmoides, M. floridanus and their F1 hybrid and identified a set of 3674 SNP markers with fixed-allelic differences from 2112 unique genes. We then developed a subset of 25 of these markers into a single diagnostic multiplex assay and validated its capacity for assessing integrity and hybridization in hatchery and wild populations of largemouth and Florida bass. The availability of this resource, high-quality transcriptomes and a large set of gene-linked SNPs, should greatly facilitate functional and population genomics studies in these key species and allow the identification of traits and processes under selection during introgressive hybridization.

Li C ，Gowan S ，Anil A ，Beck BH ，Thongda W ，Kucuktas H ，Kaltenboeck L ，Peatman E ... -  《-》

Genome-Wide Association Study of Resistance to Largemouth Bass Ranavirus (LMBV) in Micropterus salmoides.

Li P ，Luo X ，Zuo S ，Fu X ，Lin Q ，Niu Y ，Liang H ，Ma B ，Li N ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Eight single nucleotide polymorphisms and their association with food habit domestication traits and growth traits in largemouth bass fry (Micropterus salmoides) based on PCR-RFLP method.

The largemouth bass (Micropterus salmoides), an economically important freshwater fish species widely farmed in China, is traditionally cultured using a diet of forage fish. However, given the global decline in forage fish fisheries and increasing rates of waterbody pollution and disease outbreaks during traditional culturing, there is a growing trend of replacing forage fish with formulated feed in the largemouth bass breeding industry. The specific molecular mechanisms associated with such dietary transition in this fish are, nevertheless, poorly understood. To identify single nucleotide polymorphisms (SNPs) related to food habit domestication traits and growth traits in largemouth bass fry, we initially genotyped fry using eight candidate SNPs based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, with genetic parameters being determined using Popgen32 and Cervus 3.0. Subsequently, we assessed the associations between food habit domestication traits of largemouth bass fry and these SNPs using the Chi-square test or Fisher's exact test. Furthermore, we used a general linear model to assess the relationships between the growth traits of largemouth bass fry and these SNPs. The Pearson correlation coefficient between growth traits and the SNPs was also determined using bivariate correlation analysis in IBM SPSS Statistics 22. Finally, the phenotypic variation explained (PVE) by the SNPs was calculated by regression analysis in Microsoft Excel. The genotyping results obtained based on PCR-RFLP analysis were consistent with those of direct sequencing. Five SNPs (SNP01, SNP02, SNP04, SNP05, and SNP06) were found to be significantly correlated with the food habit domestication traits of fry (P < 0.05); SNP01 (P = 0.0011) and SNP04 (P = 0.0055) particularly, had showed highly significant associations. With respect to growth traits, we detected significant correlations with the two SNPs (SNP01 and SNP07) (P < 0.05), with SNP01 being significantly correlated with body length, and height (P < 0.05), and SNP07 being significantly correlated with body height only (P < 0.05). Our findings indicated that the PCR-RFLP can be used as a low-cost genotyping method to identify SNPs related to food habit domestication and growth traits in largemouth bass, and that these trait-related SNPs might provide a molecular basis for the future breeding of new varieties of largemouth bass.

Cui J ，Jiang Z ，Wang Z ，Shao J ，Dong C ，Wang L ，Li X ，Du J ，Li S ，Qiao Z ，Zhang M ... -  《PeerJ》