Pigment pattern formation in economical fish remains elusive to date. Oujiang color common carp (Cyprinus carpio var. color) is a variant of common carp with different pigmentation patterns and ...important farm fish in China. Agouti signaling protein (ASIP) is an endogenous antagonist of melanocortin in the melanogenesis pathway. In this study, two ASIP genes (ASIP 1 and ASIP 2) were first identified in color common carp. Their expression was higher in the pale belly than in the dark dorsal skin, which was consistent with the typical dorsal–ventral expression pattern such as that of wild common carp. In comparison, an unusually higher expression was detected in the non-melanophore side skin than in the melanophore side skin of Oujiang color common carp. Thus, CRISPR/Cas9 was used to disrupt the two ASIP genes in Oujiang color common carp of red with big black patches (RB) pattern. Consequently, the black patches disappeared and the melanophores dispersed along the dorsal skin in the F0 mosaic RB individuals. The findings of this study indicate that the ASIP gene is involved in regulating melanin aggregation and distribution during black patch formation in Oujiang color common carp.
•There were two ASIP genes in color common carp genome.•Black side skin showed unusually higher ASIP expression in color common carp.•Two ASIP genes were disrupted in RB at the same time.•ASIP disrupt RB color carp showed melanophores disperse to whole dorsal skin.
Acceptance of artificial pelleted diets contributes to increasing the cultured areas and output of carnivorous fish. However, the mechanism of acceptance of artificial pelleted diets remains largely ...unknown. In this study, the easy acceptance of artificial pelleted diets (EAD) group and the not easy acceptance of artificial pelleted diets (NAD) group of Largemouth bass (Micropterus salmoides) were divided based on the ratios of stomach weight/body weight (SB) after 0.5 h feeding, which was bigger than 18% in the EAD group and ranged from 8 to 12% in the NAD group. Through transcriptome and proteome sequencing, a total of 2463 differentially expressed genes (DEGs) and 230 differentially expressed proteins (DEPs) were identified, respectively. Integrated analyses of transcriptome and proteome data revealed that 152 DEPs were matched with the corresponding DEGs (named co-DEGs-DEPs), and 54 co-DEGs-DEPs were enriched in 16 KEGG pathways, including the metabolic pathways, steroid biosynthesis, fatty acid biosynthesis, etc. Furthermore, 3 terpenoid backbone biosynthesis-related genes (Hmgcr, Hmgcs, and Fdps) in metabolic pathways, 10 steroid biosynthesis-related genes (Fdft1, Sqle, Lss, Cyp51a1, Tm7sf2, Nsdhl, Hsd17b7, Dhcr24, Sc5d, and Dhcr7), and 3 fatty acid biosynthesis-related genes (Acaca, Fasn, and Ascl) were all up-regulated in the EAD group, suggesting that the lipid metabolism pathway and steroid biosynthesis pathway play important roles in early food habit domestication in Largemouth bass. In addition, the detection results of randomly selected 15 DEGs and 15 DEPs indicated that both transcriptome and proteome results in the study were reliable. Our study provides useful information for further research on the mechanisms of food habit domestication in fish.
Different contents of expanded graphite (EG) composite phase change material (PCM) were prepared by the melt mixing method, taking paraffin as the PCM and EG as the supporting material. Phase ...compositions of EG, paraffin, and EG/paraffin composite were investigated using X-ray diffraction (XRD). Microstructures of EG and EG/paraffin composite PCMs with different EG contents were observed by a scanning electron microscope (SEM). Thermal properties, such as phase-transition temperature and latent heat of the materials, were determined by differential scanning calorimetry (DSC). Mass loss and thermal properties after 100 heating cycles were measured. The results show that physical absorption exists between paraffin and EG. EG is beneficial for the PCM composite to reduce leakage of paraffin, decrease the phase change temperature and latent heat, and strengthen the thermal stability. The solid-liquid phase change latent heat of materials is larger than that of the solid-solid one. The heating cycle has little effect on the phase-transition temperature and latent heat.
In order to improve the glucose utilization capacity of largemouth bass (
Micropterus salmoides
), responses to glucose overload between two strains (Y: breeding strain; W: wild strain) were compared ...at 0, 6, 12, and 24 h after glucose injection (1.67 g/kg). The data revealed that plasma glucose in the Y strain (<12 h) recovered faster than in the W strain (12 h), with the Y strain secreted more insulin within 6 h post-injection. Triglyceride (TG) and low-density lipoprotein-cholesterol (VLDL-CH) content in the Y strain increased, peaking at 12 h, then decreased, whereas the W strain’s TG content was not affected and VLDL-CH content decreased. The hepatic and muscular fatty acid synthetase, liver x receptor-1, and sterol regulatory element-binding protein expressions were consistent with the TG content change. Both strains’ liver and muscle glycogen contents exhibited similar trends to that of the glycogen synthase gene—increasing, then declining, and peaking at 6 and 12 h. The expression levels of hepatic and muscular phosphofructokinase and pyruvate kinase in the Y strain increased, peaking at 12 h. In the W strain, they were suppressed and reached the minimum at 24 h. The mRNA levels of hepatic and muscular phosphoenolpyruvate carboxykinase and glucose-6-phosphatase were enhanced and peaked at 24 h in both strains, hepatic isocitrate dehydrogenase-1, and α-ketoglutarate dehydrogenase complex expression increased after declining, peaking at 12 and 24 h. Two genes in the W strain’s muscles showed a similar trend. Both strains’ transcriptome results identified seven common functional genes for resistance to hyperglycemia that were involved in the circadian rhythm pathway, which is a suggested key pathway for coping with hyperglycemia. Furthermore, 48 differential genes were identified between the two strains, and these genes were enriched in the TGF-beta and cell cycle signaling pathways, indicating that these pathways may be key factors affecting the differential responses to glucose overload. We conducted a comprehensive comparison of glucose overload molecular responses between two strains of
M. salmoides
, and the results can provide a promising strategy to improve the glucose utilization capacity of
M. salmoides
based on advantageous pre-existing traits.
Affected by the continuously rising temperature, thermal stress leads to a delinked growth rate and resistance to stress in cultured largemouth bass (
, LMB) in China. Identification of LMB with ...better thermal resistance will benefit the breeding of new varieties. However, there has been limited reporting on the evaluation to identify LMB with better thermal resistance. LMB consists of the northern LMB (
, NLMB) and the Florida LMB (
, FLMB). Due to their different geographical distributions, it has been suggested that FLMB exhibit better thermal resistance compared to NLMB. In this study, NLMB and FLMB were subjected to thermal stress for 3 h (acute) and 60 d (chronic) at 33 °C, respectively. Subsequently, the variations of 12 candidate biomarkers between NLMB and FLMB were analyzed. Exposure to acute thermal stress significantly increased plasma cortisol, blood glucose, and lactate levels; activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glucose kinase (GK), pyruvate kinase (PK), lactate dehydrogenase (LDH), and glucose 6 phosphatase (G6Pase); and the expressions of
and
in both NLMB and FLMB (
< 0.05). Compared to NLMB, FLMB exhibited a lower plasma cortisol level and a higher expression of
under acute thermal stress (
< 0.05). Exposure to chronic thermal stress significantly increased plasma cortisol and blood glucose levels, as well as activities of GK, PK, LDH, and G6Pase, as well as expressions of
and
in both NLMB and FLMB (
< 0.05). Additionally, FLMB showed a lower expression of
compared to NLMB (
< 0.05). In conclusion, our results showed that LMB with lower plasma cortisol level and higher expression of
under acute thermal stress, as well as lower expression of
under chronic thermal stress were suggested to have better thermal resistance. Our study provides valuable information for identifying and breeding LMB varieties with better thermal resistance in the future.
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.
The largemouth bass (
), 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 (
< 0.05); SNP01 (
= 0.0011) and SNP04 (
= 0.0055) particularly, had showed highly significant associations. With respect to growth traits, we detected significant correlations with the two SNPs (SNP01 and SNP07) (
< 0.05), with SNP01 being significantly correlated with body length, and height (
< 0.05), and SNP07 being significantly correlated with body height only (
< 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.
Largemouth bass (
Micropterus salmoides
) is an economically important species in China. Contrary to its rapidly increasing yield during the last decades, the domestic genetic diversity of largemouth ...bass has gradually declined. In this study, 37 single nucleotide polymorphism (SNP) markers were developed based on genotyping-by-sequencing data and characterized by genotyping 32 individuals using the PCR–restriction fragment length polymorphism method. The effective number of alleles (
Ne
), observed heterozygosity (
Ho
), expected heterozygosity (
He
), and polymorphic information content (
PIC
) of these SNPs ranged from 1.168 to 1.998, 0.156 to 0.844, 0.146 to 0.507, and 0.134 to 0.375, respectively. Totally, five loci deviated significantly from Hardy–Weinberg equilibrium (
p
< 0.05), while there existed no linkage disequilibrium at all loci. These novel polymorphic markers will lay the foundation for future rationally excavation and utilization of germplasm resources in
M. salmoides
.
Aim of study: To investigate action mechanism of Yi Guan Jian Decoction on cirrhosis induced by CCl₄ in rats. Material and methods: CCl₄ (3mL/kg) for the first time and then olive oil CCl₄ solution ...50% (2mL/kg) was administered hypodermically to rats twice each week for 12 weeks. At the end of 8th week, rats were randomly divided into CCl₄ control group (n =10), Yi Guan Jian Decoction group (n =9) and Xiao Chai Hu Decoction group (n =9). Yi Guan Jian Decoction and Xiao Chai Hu Decoction were oral administrated per day respectively for 4 weeks, concomitantly continued CCl₄ administration. At 12th weekend, the rats were sacrificed for sampling and detection of liver function, histological changes of liver tissue, liver tissue hydroxyproline content and expression of α-SMA, CD68, MMP-13, TIMP-1, TIMP-2, Caspase-12, HGFα, MMP-2, MMP-9 and hepatocyte apoptotic index. Results and conclusions: (1) Compared with that of normal rats, expression of α-SMA, CD68 and TIMP-1 in liver tissue of 8 week model group rats increases significantly (P <0.01), moreover further increased in the 12 week of model group. However, MMP-13, HGFα, TIMP-2 content decreases gradually and the statistical difference is seen between each time point (P <0.01). Activity of MMP-2, MMP-9, content of Caspase-12 and hepatocyte apoptotic index increased gradually at 4th, 8th, 12th week. (2) Compared to that of the same time point model group, activity of MMP-9 and contents of MMP-13, TIMP-2 and HGFα in Yi Guan Jian Decoction group improves significantly (P < 0.01), and activity of MMP-2 and contents of α-SMA, TIMP-1, Caspase-12 and hepatocyte apoptotic index decreases significantly (P < 0.01). This work suggests that Yi Guan Jian Decoction exerts significant therapeutic effect on CCl₄-induced cirrhosis in rats, through mechanism of inhibiting hepatocytes apoptosis and hepatic stellate cells activation, and regulating the function of Kupffer cell. Ethnopharmacological relevance: This study investigates the mechanism of Yi Guan Jian against cirrhosis from aspect of heptocytes apoptosis and hepatic stellate cells activation. It suggest that although of unknown bioactive ingredients, mechanism of traditional Chinese medicine recipe against cirrhosis can be disclosed and of profound significance.
Sex dimorphism of economic traits such as growth rate and body size have potential breeding value in aquaculture. Largemouth bass (Micropterus salmoides L.) is an important freshwater cultured fish ...in China and the females live longer and reach larger sizes than males. However, the lacking of sex-specific makers and the unclear sex determination mechanism inhibits the development of all-female breeding. In this study, 5 females and 5 males were randomly selected and sequenced with whole-genome re-sequencing technology. In total, 1394 filtered SNPs and 425 filtered InDels were finally identified, and most of these makers were located at Chr7 and Chr18. The validation of the 35 SNPs located at Chr7 in three distinct population (n = 72) indicated that 2 SNPs (S4 and S6) could distinguish the females and males with 100% accuracies, which were genotyped as CC and CG, AA and AT in the females and males, respectively. Further, 10 and 6 InDels with sizes more than 18 bp were finally screened out on Chr7 and Chr18. 2 male-specific InDels (rs3394676 and rs3496814) located at Chr7 could effectively distinguish the above females and males with a PCR-based agarose gel electrophoresis, which performed as one band in the females and two bands in the males, respectively. These results suggested the Chr7 might be the sex chromosome and a XX/XY sex determination system in largemouth bass. In conclusion, a whole-genome re-sequencing method was first conducted to provide usefulness sex-specific makers and a XX/XY sex determination system in largemouth bass, which contributes to study of the sex determination mechanisms and the development of mono-sex population breeding.
•Whole-genome re-sequencing were first conducted to explore the genetic differences between males and females in largemouth bass.•Two male-specific SNPs and two male-specific InDels were developed to distinguish genetic sex of largemouth bass.•The chromosome 7 was the sex chromosome in largemouth bass.•The sex determination system was a XX/XY determination system in largemouth bass.
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