Genome最新文献

Several pathogens, including nematodes, have severe effects on plant development and growth, and immense populations of parasitic nematodes may cause plant death and crop loss. Obligate plant-parasitic nematodes and root-knot nematodes belonging to the genus Meloidogyne are significant parasites in crops. During nematode infection, damage-associated molecular patterns play a role in the activation of plant defence responses to pathogens. Several genes are involved in Meloidogyne parasitism. However, the expression of nematode-responsive genes CRF1, WRKY45, and PR7 during infection with different parasitic nematode species is not well understood. Therefore, this study aimed to reveal plant responses to differential gene expression of nematode-responsive genes in tomato plants, and their relationship to nematode reproduction and comparative phylogeny. Molecular methods for gene expression, greenhouse work for nematode reproduction, and phylogenetic analysis were used to determine nematode-plant interactions. The results revealed that differential gene expression of CRF1, WRKY45, and PR7 depended on the nematode species. The relative CRF1 gene expression reached its highest level at 3 dpi, following nematode infection. In conclusion, plant defense responses disturbed the expression of nematode-responsive genes, and the differential expression of nematode-responsive genes was affected by nematode species and nematode parasitism.

An albino infant wallaby was born to a mother with wild-type body color. PCR and sequencing analyses of TYR (encoding tyrosinase, which is essential for melanin biosynthesis) of this albino wallaby revealed a 7.1-kb-long DNA fragment inserted in the first exon. Since the fragment carried long terminal repeats, we assumed it to be a copy of an endogenous retrovirus, which we named walb. We cloned other walb copies residing in the genomes of this species and of another wallaby species. The copies exhibited length variation, and the longest copy (>8.0 kb) contained open reading frames whose deduced amino acid sequences were well aligned with those of gag, pol, and env of retroviruses. It is unknown through which of the following likely processes the walb copy was inserted into TYR: endogenization (infection of a germline cell by an exogenous virus), reinfection (infection by a virus produced from a previously endogenized provirus), or retrotransposition (intracellular relocation of a provirus). In any case, the insertion into TYR is considered to have been a recent event on an evolutionary timescale because albino mutant alleles generally do not persist for long because of their deleterious effects in wild circumstances.

Genomic reorganization, such as rearrangements and inversions, influences how genetic information is organized within the bacterial genomes. Inversions, in particular, facilitate genome evolution through gene gain and loss, and can alter gene expression. Previous studies have investigated the impact inversions have on gene expression induced inversions targeting specific genes or examine inversions between distantly related species. This fails to encompass a genome-wide perspective of naturally occurring inversions and their post-adaptation impact on gene expression. Here, we used bioinformatic techniques and multiple RNA-seq datasets to investigate the short- and long-range impact inversions have on genomic gene expression within Escherichia coli. We observed differences in gene expression between homologous inverted and non-inverted genes even after long-term exposure to adaptive selection. In 4% of inversions representing 33 genes, differential gene expression between inverted and non-inverted homologs was detected, with greater than two-thirds (71%) of differentially expressed inverted genes having 9.4-85.6-fold higher gene expression. The identified inversions had more overlap than expected with nucleoid-associated protein binding sites, which assist in the regulation of genomic gene expression. Some inversions can drastically impact gene expression, even between different strains of E. coli, and could provide a mechanism for the diversification of genetic content through controlled expression changes.

Bos indicus cattle breeds have been naturally selected for thousands of years for disease resistance and thermo-tolerance. However, the genetic mechanisms underlying these specific inherited characteristics must be elucidated. Hence, in this study, a whole-genome comparative analysis of the Bos indicus cattle breeds Kangayam, Tharparkar, Sahiwal, Red Sindhi, and Hariana of the Indian subcontinent was conducted. Genetic variant identification analysis revealed 155 851 012 SNPs and 10 062 805 InDels in the mapped reads across all Bos indicus cattle breeds. The functional annotation of 17 252 genes that comprised both SNPs and InDels, with high functional impact on proteins, was carried out. The functional annotation results revealed the pathways involved in the innate immune response, including toll-like receptors, retinoic acid-inducible gene I-like receptors, NOD-like receptors, Jak-STAT signaling pathways, and non-synonymous variants in the candidate immune genes. We also identified several pathways involved in the heat shock response, hair and skin properties, oxidative stress response, osmotic stress response, thermal sweating, feed intake, metabolism, and non-synonymous variants in the candidate thermo-tolerant genes. These pathways and genes directly or indirectly contribute to the disease resistance and thermo-tolerance adaptations of Bos indicus cattle breeds.

The avian pectoralis muscle demonstrates plasticity with regard to size, so that temperate birds facing winter conditions or birds enduring a migration bout tend to have significant increases in the size and mass of this tissue due to muscular hypertrophy. Myonuclear domain (MND), the volume of cytoplasm a myonuclei services, in the pectoralis muscle of birds seems to be altered during thermal stress or changing seasons. However, there is no information available regarding muscle DNA content or ploidy level within the avian pectoralis. Changes in muscle DNA content can be used in this tissue to aid in size and mass changes. Here, we hypothesized that long-distance migrants or temperate residents would use the process of endoreduplication to aid in altering muscle size. Mostly contradictory to our hypotheses, we found no differences in the mean muscle DNA content in any of the 62 species of birds examined in this study. We also found no correlations between mean muscle DNA content and other muscle structural measurements, such as the number of nuclei per millimeter of fiber, myonuclear domain, and fiber cross-sectional area. Thus, while avian muscle seems more phenotypically plastic than mammalian muscle, the biological processes surrounding myonuclear function may be more closely related to those seen in mammals.

Despite several studies on genetic markers and differentially expressed genes related to ribeye area (REA) and tenderness traits in beef cattle, there is divergence in the results regarding the genes associated with these traits. Thirteen genes associated with or exhibiting biological functions that might influence such phenotypes were included in this study. A total of five genes for REA (IGF-1, IGF-2, MSTN, NEDD4, and UBE4A) and eight genes for meat tenderness (CAPN1, CAPN2, CAST, HSPB1, DNAJA1, FABP4, SCD, and PRKAG3) were selected from previous studies on beef cattle. Genes and their respective proteins expression were validated in a commercial population of Nellore cattle using quantitative real-time PCR (RT-qPCR) and advanced mass spectrometry (LC/MS-MS) techniques, respectively. The MSTN gene was upregulated in animals with low REA. The CAPN1, CAPN2, CAST, HSPB1, and DNAJA1 genes were upregulated in animals with tough meat. The proteins translated by these genes were not differentially expressed. Our results confirm the potential of some of the studied genes as biomarkers for carcass and meat quality traits in Nellore cattle.

The C2H2-type zinc finger protein (ZFP) family is one of the largest transcription factor families in the plant kingdom and its members are involved in plant growth, development, and stress responses. As an economically valuable perennial graminaceous forage crop, orchardgrass (Dactylis glomerata) is an important feedstuff resource owing to its high yield and quality. In this study, 125 C2H2-type ZFPs in orchardgrass (Dg-ZFPs) were identified and further classified by phylogenetic analysis. The members with similar gene structures were generally clustered into the same groups, with proteins containing the conserved QALGGH motif being concentrated in groups VIII and IX. Gene ontology and miRNA target analyses indicated that Dg-ZFPs likely perform diverse biological functions through their gene interactions. The RNA-seq data revealed differentially expressed genes across tissues and development phases, suggesting that some Dg-ZFPs might participate in growth and development regulation. Abiotic stress responses of Dg-ZFP genes were verified by qPCR and Saccharomyces cerevisiae transformation, revealing that Dg-ZFP125 could enhance the tolerance of yeasts to osmotic and salt stresses. Our study performed a novel systematic analysis of Dg-ZFPs in orchardgrass, providing a reference for this gene family in other grasses and revealing new insights for enhancing gene utilization.