Insights into genetic diversity and phenotypic variations in domestic geese through comprehensive population and pan-genome analysis

Background Domestic goose breeds are descended from either the Swan goose(Anser cygnoides)or the Greylag goose(Anser anser),exhibiting variations in body size,reproductive performance,egg production,feather color,and other phenotypic traits.Constructing a pan-genome facilitates a thorough identification of genetic variations,thereby deepening our comprehension of the molecular mechanisms underlying genetic diversity and phenotypic variability.Results To comprehensively facilitate population genomic and pan-genomic analyses in geese,we embarked on the task of 659 geese whole genome resequencing data and compiling a database of 155 RNA-seq samples.By constructing the pan-genome for geese,we generated non-reference contigs totaling 612 Mb,unveiling a collection of 2,813 novel genes and pinpointing 15,567 core genes,1,324 softcore genes,2,734 shell genes,and 878 cloud genes in goose genomes.Furthermore,we detected an 81.97 Mb genomic region showing signs of genome selection,encompassing the TGFBR2 gene correlated with variations in body weight among geese.Genome-wide association studies utilizing single nucleotide polymorphisms(SNPs)and presence-absence variation revealed significant genomic associations with various goose meat quality,reproductive,and body composition traits.For instance,a gene encoding the SVEP1 protein was linked to carcass oblique length,and a distinct gene-CDS haplotype of the SVEP1 gene exhibited an association with carcass oblique length.Notably,the pan-genome analysis revealed enrichment of variable genes in the“hair follicle maturation”Gene Ontology term,potentially linked to the selection of feather-related traits in geese.A gene presence-absence variation analysis suggested a reduced frequency of genes associated with“regulation of heart contraction”in domesticated geese compared to their wild counterparts.Our study provided novel insights into gene expression features and functions by integrating gene expression patterns across multiple organs and tissues in geese and analyzing population variation.Conclusion This accomplishment originates from the discernment of a multitude of selection signals and candidate genes associated with a wide array of traits,thereby markedly enhancing our understanding of the processes underlying domestication and breeding in geese.Moreover,assembling the pan-genome for geese has yielded a comprehensive apprehension of the goose genome,establishing it as an indispensable asset poised to offer innovative viewpoints and make substantial contributions to future geese breeding initiatives.

Measurement of left ventricular fluid dynamic parameters in healthy Chinese adults based on echocardiographic vector flow mapping

To the Editor:As we concerdered that there was barely any widely representative,recognized,and standardized echocardiographic vector flow mapping(VFM)method has been established for the observation and measurement of the blood flow in cardiac cavities in clinical practice,and there were no commonly accepted normal reference values for Chinese adults have been obtained till now,hindering the further promotion and application of this technology in clinical practice.Establishing normal reference values for echocardiographic VFM that can be widely accepted in clinical practice is of great significance for determining the normal or abnormal fluid dynamic status in the left ventricle(LV)chamber.

ATP Stress Myocardial Contrast Echocardiography Assessment of Coronary Microvascular Disease with Spasmodic Characteristics: A Case Report

Here, a patient with chest pain and <50% stenosis on coronary angiography, where ATP stress myocardial contrast echocardiography (MCE) revealed that coronary flow reserve was reduced to 1.71 was presented. Perfusion delay occurred in the left ventricular wall of the apex of the heart before ATP stress, and the perfusion delay area was significantly reduced at peak stress. Similar to the characteristics of "reverse redistribution" of radionuclide myocardium perfusion in coronary vasospasm, the delayed perfusion area in the recovery period was larger than that detected before stress. Together with increased spectral resistance of the distal segment of left anterior descending coronary artery and chest pain, these findings indicated coronary microvascular disease with spasmodic characteristics in this patient. The perfusion characteristics on ATP stress determined by MCE and changes in coronary spectrum have value for the diagnosis and treatment of coronary microvascular disease with spasmodic characteristics.