Genetic Factors Research Articles

Discordant Sibling Pair Comparisons in Observational Studies: A Research Design Simply Explained.

When studying how (eg) gestational exposure to antidepressant drugs influences the risk of (eg) autism spectrum disorder (ASD) in offspring, conventional observational studies adjust analyses for available covariates and confounds. In such analyses, a significant association between antidepressant exposure and ASD outcome can never be asserted to be causal because of the possibility of residual confounding arising from confounding by indication (or severity thereof), confounding by genetic risk factors, and confounding by environmental risk factors. Confounding by indication and severity thereof can sometimes be addressed through propensity score matching, but the adjustment can never be perfect. Additionally, adjustment for genetic and environmental risk factors is hard or impossible to do because these are inadequately measured, unmeasured, and/or unknown variables. Sibling comparison studies have recently emerged as an option to address the genetic and environmental risk factors. In such studies, sibs discordant for exposure are compared for risk of outcome (cohort design) or sibs discordant for outcome are compared for odds of exposure (case-control design). The assumption is that sibs share similar genetic and environmental risk factors and so, when sibs are compared, these risk factors cancel out whether they are measured or not, known or unknown. If antidepressant exposure remains significantly associated with ASD in sibling comparisons, a possible conclusion is that antidepressants and not genetic or environmental factors drive the ASD risk. If antidepressant exposure loses significance in the sibling comparisons, it suggests that shared genetic and/or environmental factors, rather than antidepressant exposure, explain the ASD risk. The interpretation, however, is nuanced. Strengths, limitations, and interpretations of sibling comparison studies are explained. To illustrate the usefulness of sibling comparisons, results are presented from a recent study of ASD risk after gestational or early infancy exposure to antibiotics.

Impact of Cancer Cachexia Progression on OATP1B1 Transport Activity: Quantitative Analysis Using Coproporphyrin-I as an Endogenous Biomarker.

Genetic factors, inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), and uremic substances such as 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) have been reported to affect organic anion transporting polypeptide (OATP)1B1 transport activity. However, the relationship between OATP1B1 transport activity and these factors in patients with cancer cachexia has not been reported. This study aimed to identify the factors contributing to individual differences in OATP1B1 transport activity in patients with cancer cachexia, using coproporphyrin-I (CP-I) as an endogenous biomarker of OATP1B1 transport activity. The study recruited 114 patients with cancer cachexia who satisfied the selection criteria. The subjects were classified into pre-cachexia, cachexia, and refractory cachexia. Median [interquartile range] plasma CP-I level was higher in patients with pre-cachexia (0.91 [0.67-1.12] ng/mL) compared with the data in the general population reported previously and tended to be higher in patients with refractory cachexia (1.06 [0.78-1.64] ng/mL) than in those with cachexia (0.87 [0.62-1.07] ng/mL), suggesting that OATP1B1 transport activity may decrease with the progression of cancer cachexia. Plasma CP-I correlated positively with IL-6 and TNF-α concentrations but did not correlate with OATP1B1 polymorphisms or CMPF concentration, which have been reported to reduce transport activity. Multiple regression analysis using the forced entry method identified refractory cachexia as a significant factor independently affecting plasma CP-I concentration. These findings suggest that the reduction in OATP1B1 transport activity in patients with cancer cachexia may be attributed to inflammatory cytokines or some other factors that are elevated by cancer cachexia progression, rather than OATP1B1 polymorphisms and CMPF.

Telomeres and Human Disease.

Telomeres, the long nucleotide repeats, and protein complex at chromosome ends, are central to genomic integrity. Telomere length (TL) varies widely between populations due to germline genetics, environmental exposures, and other factors. Very short telomeres caused by pathogenic germline variants in telomere maintenance genes cause the telomere biology disorders, a spectrum of life-threatening conditions including bone marrow failure, liver and lung disease, cancer, and other complications. Cancer predisposition with long telomeres is caused by rare pathogenic germline variants in components of the shelterin telomere protection protein complex and associated primarily with elevated risk of melanoma, thyroid cancer, sarcoma, and lymphoproliferative malignancies. In the middle, studies of the general population at risk of common illnesses, such as cardiovascular disease and cancer, have found statistically significant differences in TL but uncertain clinical applicability. This work reviews connections between telomere biology and human disease focusing on similarities and differences across the phenotypic spectrum.

Role of hepatotropic viruses in promoting hepatocellular carcinoma-current knowledge and recent advances.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with chronic infections by hepatotropic viruses such as hepatitis B virus (HBV), and hepatitis C virus (HCV), being major risk factors. Chronic infections with these viruses are the leading cause of HCC worldwide, with HBV alone responsible for over 50% of cases. Despite advances in direct-acting antivirals (DAAs) for HCV and nucleos(t)ide analogues (NAs) for HBV, challenges remain in HCC prevention, early detection, and treatment. Recent research highlights the role of viral-induced metabolic alterations, such as the Warburg effect, mitochondrial dysfunction, and lipid dysregulation, in promoting HCC. Moreover, immune checkpoint inhibitors have emerged as effective treatments for advanced HCC, though responses vary between HBV- and HCV-related cancers. Additionally, novel therapeutic approaches and metabolic-targeted therapies offer promising avenues for virus-associated HCC treatment. Advancements in liquid biopsy biomarkers and artificial intelligence-driven diagnostics are improving HCC surveillance and risk stratification, potentially enabling earlier interventions. While HBV vaccination has significantly reduced HCC incidence, disparities in global vaccination coverage persist. Furthermore, antiviral therapies combined with structured surveillance programs have proven effective in reducing HCC incidence and mortality. This review highlights the complex connection between viral, genetic, and environmental factors in HCC development and underscores the importance of integrated prevention strategies to reduce its burden globally.

Association of the RET Intronic Variant rs2435357 on Hirschsprung’s Disease Susceptibility: A Systematic Review and Meta-Analysis

Background: Hirschsprung disease (HSCR) is a congenital life-threatening intestinal disorder characterized by the absence of nerves in the myenteric and submucosal plexuses in the distal bowel. There are several studies on the association of rs2435357 polymorphism in the proto-oncogene RET gene and HSCR susceptibility. However, some of the results remain controversial. Therefore, we conducted this updated meta-analysis to estimate the association of this polymorphism and HSCR risk. Methods: We searched PubMed, Scopus, Web of Science and Google Scholar according to PRISMA guidelines to assess the association of RET rs2435357 with HSCR up to Jan 2024. We included case-control/cohort studies to perform meta-analysis conducted using genotype models. Odd ratios (ORs) with 95%CI were utilized to determine the susceptibility to HSCR. Q-test and I2 were used to evaluate heterogeneity, and Egger’s/ Begg’s tests were used to assess publication bias. Results: Overall, 89 eligible studies meeting the inclusion criteria were retrieved with 2690 cases and 5408 controls from online databases. Finally, 17 studies were used for meta-analysis. RET rs2435357 showed a statistically significant association with HSCR under allelic model (OR = 4.50, 95%CI: 3.78-5.36, P<0.05), additive model (OR=2.02, 95%CI: 1.54-2.63, P<0.05), recessive model (OR=4.39, 95%CI: 3.33-5.78, P<0.05) and dominant model (OR=8.66, 95%CI: 6.96-10.76, P<0.05). Conclusion: The polymorphism rs2435357 in RET gene provides substantial susceptibility in all inheritance models and to HSCR. However, more research is needed to clarify its specific role in prognosis and the interaction with other genetic and environmental factors affecting HSCR.

Interaction Between Traffic-Related Air Pollution and Parkinson Disease Polygenic Risk Score

Genetic and environmental factors are linked to Parkinson disease (PD), but the role of genetic susceptibility in the association between traffic-related air pollution (TRAP) and PD remains unclear. To assess the gene-environment interaction between the polygenic risk score (PRS) for PD and long-term TRAP exposure and to estimate the joint effect with PD risk. This population-based case-control study used a meta-analytical assessment of studies conducted in central California and Denmark. The Parkinson Environment and Genes (PEG) study in California (June 1, 2000, to July 31, 2017) included 634 patients with PD and 733 controls; the Parkinson Disease in Denmark (PASIDA) study (January 1, 2006, to December 31, 2017) included 966 patients with PD and 1045 controls. Data were analyzed from July 1 to October 31, 2024. PRS was computed by summing the effect estimates of well-known risk alleles from an existing genome-wide association study's summary statistics using participants' genetic arrays. TRAP exposure was estimated using dispersion models to calculate long-term exposure (10- or 15-year means with a 5-year lag) to traffic-related pollutants (represented by carbon monoxide [CO] levels) at participants' residences. The main outcome was diagnosis of PD. Using multivariable logistic regression, PD risk was estimated from interactions between PRS (per SD) and TRAP exposure (per IQR), with joint effects based on low (quartiles 1-3) and high (quartile 4) exposure levels. A total of 1600 patients with PD (mean [SD] age, 65.1 [9.9] years; 990 [61.9%] male) and 1778 controls (mean [SD] age, 64.5 [10.3] years; 992 [55.8%] male) were included. Meta-analytical estimates suggest that both higher PRS and increased TRAP exposure increased PD risk, with an interaction effect estimate of 1.06 (95% CI, 1.00-1.12). Joint effect analysis indicated that individuals with both high PRS and high TRAP exposure were at greatest risk of PD (odds ratio, 3.05; 95% CI, 2.23-4.19) compared with the reference group with a low PRS and low TRAP exposure, suggesting a synergistic effect. In this gene-environment interaction study, a combination of long-term air pollution exposure and genetic susceptibility strongly contributed to the risk of developing PD. Widespread exposure to air pollution makes TRAP an important modifiable risk factor affecting large populations globally, particularly individuals with genetic vulnerability.

The influence of genetic factors on the clinical manifestations and response to systemic treatment of plaque psoriasis.

Plaque psoriasis is a common, chronic, papulosquamous skin disorder. TNF, IL-17 and IL-23 have been identified as key cytokines in the pathogenesis of psoriasis. Certain human leukocyte antigen (HLA) variants, such as HLA-Cw6 and HLA-B27, were proposed to affect the clinical course of the disease and the response to standard and biological treatment. In individuals positive for HLA-B27, psoriatic arthritis tends to progress more rapidly, with a higher prevalence of dactylitis and nail changes, suggesting HLA-B27 being a genetic biomarker for early-onset psoriatic arthritis. HLA-Cw6 is associated with the early onset of cutaneous manifestations in psoriasis. In these cases, cutaneous lesions are commonly localised on the chest and limbs, with less pronounced scalp and nail involvement. Psoriatic arthritis tends to develop later in HLA-Cw6-positive patients. The presence of HLA-Cw6 is associated with a more favourable therapeutic response to methotrexate and p40IL-12/23 inhibitors than to TNF inhibitors. Therefore, HLA-Cw6 testing may be a valuable tool for identifying patients who are likely to benefit from treatment with specific monoclonal antibodies, especially p40IL-12/23 inhibitors.

Transcriptional heterogeneity shapes stress-adaptive responses in yeast

In response to stress, cells activate signaling pathways that coordinate broad changes in gene expression to enhance cell survival. Remarkably, complex variations in gene expression occur even in isogenic populations and in response to similar signaling inputs. However, the molecular mechanisms underlying this variability and their influence on adaptive cell fate decisions are not fully understood. Here, we use scRNA-seq to longitudinally assess transcriptional dynamics during osmoadaptation in yeast. Our findings reveal highly heterogeneous expression of the osmoresponsive program, which organizes into combinatorial patterns that generate distinct cellular programs. The induction of these programs is favored by global transcriptome repression upon stress. Cells displaying basal expression of the osmoresponsive program are hyper-responsive and resistant to stress. Through a transcription-focused analysis of more than 300 RNA-barcoded deletion mutants, we identify genetic factors that shape the heterogeneity of the osmostress-induced transcriptome, define regulators of stress-related subpopulations and find a link between transcriptional heterogeneity and increased cell fitness. Our findings provide a regulatory map of the complex transcriptional phenotypes underlying osmoadaptation in yeast and highlight the importance of transcriptional heterogeneity in generating distinct adaptive strategies.

The significance of Itga8 and Vangl2 in kidney development: Insights from yotari mice.

The significance of Itga8 and Vangl2 in kidney development: Insights from yotari mice.

Associations between RetNet gene polymorphisms and the efficacy of orthokeratology for myopia control: a retrospective clinical study

BackgroundThis study investigated how clinical and genetic factors impact the effectiveness of orthokeratology lenses in myopia.MethodsA retrospective clinical study was conducted with a sample of 545 children aged 8–12 years who had myopia and have initially worn orthokeratology lenses for one year. Whole-genome sequencing (WGS) was also performed on 60 participants in two groups, one with rapid axial length (AL) progression of larger than 0.33 mm and the other with slow AL progression of less than 0.09 mm. The RetNet database was used to screen candidate genes that may contribute to the effectiveness of orthokeratology lenses in controlling myopia.ResultsChildren with greater baseline AL, greater spherical equivalent (SE) and greater age had better myopia control with orthokeratology lenses. A significant excess of nonsynonymous variants was observed among those with slow myopia progression, and these were prominently enriched in retinal disease-related genes. Subsequently, RIMS2 [odds ratio (OR) = 0.01, P = 0.0097] and LCA5 (OR = 9.27, P = 0.0089) were found to harbor an excess number of nonsynonymous variants in patients with slow progression of high myopia. Two intronic common variants rs36006402 in SLC7A14 and rs2285814 in CLUAP1 were strongly associated with AL growth. The identification of these novel genes associated with the effectiveness of orthokeratology lens therapy in myopic children provides insight into the genetic mechanism of orthokeratology treatment.ConclusionThe effectiveness of orthokeratology lens treatment relates to interindividual variability in the control of AL growth in myopic eyes. The efficacy increased when patients carried more nonsynonymous variants in retinal disease-related gene sets. These data serve as reference for genetic counselling and the management of patients who choose orthokeratology lenses to control myopia.

State-of-the-Art Review on the Treatment of Axial Spondyloarthritis

The term axial spondyloarthritis (axSpA) encompasses patients with both radiographic (r-axSpA) and non-radiographic (nr-axSpA) forms of the disease. These are two entities within the same family that share many genetic and pathogenic factors, but they also have significant differences. For example, the male-to-female ratio is 2:1 in r-axSpA and 1:1 in nr-axSpA. Additionally, the prevalence of the HLA-B27 gene is notably higher in r-axSpA. Early diagnosis remains an unmet need, with magnetic resonance imaging (MRI) being the most important tool for diagnosis and disease monitoring. Early detection is crucial, as it allows for timely treatment, increasing the chances of preventing new bone formation and long-term structural bone damage. Various cytokines, such as tumor necrosis factor (TNF)-α and interleukin-17, play active roles in the disease’s pathogenesis, although the exact mechanisms of interaction are not yet fully understood. Clarifying these mechanisms will be key to developing new classification criteria, screening methods, and more personalized, targeted therapies. Non-steroidal anti-inflammatory drugs (NSAIDs), TNF inhibitors, interleukin-17 blockers, and, more recently, Janus kinase (JAK) inhibitors, are the most effective treatments for both radiographic and non-radiographic axial spondyloarthritis.

Genetic compatibility and ecological connectivity drive the dissemination of antibiotic resistance genes

The dissemination of mobile antibiotic resistance genes (ARGs) via horizontal gene transfer is a significant threat to public health globally. The flow of ARGs into and between pathogens, however, remains poorly understood, limiting our ability to develop strategies for managing the antibiotic resistance crisis. Therefore, we aim to identify genetic and ecological factors that are fundamental for successful horizontal ARG transfer. We used a phylogenetic method to identify instances of horizontal ARG transfer in ~1 million bacterial genomes. This data was then integrated with >20,000 metagenomes representing animal, human, soil, water, and wastewater microbiomes to develop random forest models that can reliably predict horizontal ARG transfer between bacteria. Our results suggest that genetic incompatibility, measured as nucleotide composition dissimilarity, negatively influences the likelihood of transfer of ARGs between evolutionarily divergent bacteria. Conversely, environmental co-occurrence increases the likelihood, especially in humans and wastewater, in which several environment-specific dissemination patterns are observed. This study provides data-driven ways to predict the spread of ARGs and provides insights into the mechanisms governing this evolutionary process.

Role of FOXP3 (rs3761548) Polymorphism in Modulating FOXP3 Protein Level in Iraqi Patients with Thyroid Disorder

Background: Thyroid disorders are a major clinical concern that negatively impacts the thyroid gland. Thyroid issues have been connected to the FOXP3 gene, which is an important immune system regulator. FOXP3 protein levels can be affected by genetic differences, which may impair regulatory T-cell activity and exacerbate immunological abnormalities. Objectives: To investigate the influence of FOXP3 gene polymorphisms on circulating FOXP3 protein levels and their association with thyroid dysfunction. Methods: This study included 100 patients with thyroid disorders and 50 healthy controls. Thyroid function was assessed by measuring serum T3, T4, and TSH levels using a Cobas analyzer. Serum FOXP3 protein levels were quantified by ELISA. Genomic DNA was extracted and analyzed for FOXP3 gene variations using PCR and sequencing. Results: No significant differences were observed in serum T3 and T4 levels between patients and controls. However, TSH levels were significantly elevated in the patient group. Serum FOXP3 levels were significantly lower in patients compared to controls. The distribution of the three FOXP3 gene genotypes (AA, AC, and CC) did not differ significantly between patients and controls. Individuals with the heterozygous (AC) genotype exhibited significantly higher serum FOXP3 levels compared to the other two genotypes. Conclusions: Individuals with thyroid disorders had reduced levels of FOXP3, which may indicate an association between thyroid disease and impaired immunity. The study emphasizes the complicated interaction of genetic and environmental factors, even if it could not identify an obvious connection with the rs3761548 gene variation.

Exploring the shared genetic landscape of diabetes and cardiovascular disease: findings and future implications.

Diabetes is a rapidly growing global health concern projected to affect one in eight adults by 2045, which translates to roughly 783 million people. The profound metabolic alterations often present in dysglycaemia significantly increase the risk of cardiovascular complications. While genetic susceptibility plays a crucial role in diabetes and its vascular complications, identifying genes and molecular mechanisms that influence both diseases simultaneously has proven challenging. A key reason for this challenge is the pathophysiological heterogeneity underlying these diseases, with multiple processes contributing to different forms of diabetes and specific cardiovascular complications. This molecular heterogeneity has limited the effectiveness of large-scale genome-wide association studies (GWAS) in identifying shared underlying mechanisms. Additionally, our limited knowledge of the causal genes, cell types and disease-relevant states through which GWAS signals operate has hindered the discovery of common molecular pathways. This review highlights recent advances in genetic epidemiology, including studies of causal associations that have uncovered genetic and molecular factors influencing both dysglycaemia and cardiovascular complications. We explore how disease subtyping approaches can be critical in pinpointing the unique molecular signatures underlying both diabetes and cardiovascular complications. Finally, we address critical research gaps and future opportunities to advance our understanding of both diseases and translate these discoveries into tangible benefits for patient care and population health.

A Survey on Artificial Intelligence in Precision Medicine and Healthcare Analysis for Neonatal Surgery

Artificial Intelligence (AI) has emerged as a transformative force in precision medicine, healthcare analysis, and neonatal surgery, enabling personalized treatment, early disease detection, and optimized clinical decision-making. This survey explores the evolving role of AI in healthcare, focusing on its applications, challenges, and future prospects. AI-driven approaches, including machine learning (ML) and deep learning (DL), have demonstrated remarkable accuracy in medical imaging, genomics, drug discovery, neonatal diagnostics, and patient risk assessment. These technologies enhance diagnostic precision, facilitate predictive analytics, and support real-time monitoring of chronic diseases and neonatal conditions. Precision medicine, which tailors treatments based on an individual’s genetic, environmental, and lifestyle factors, benefits significantly from AI-powered analytics. The integration of AI with electronic health records (EHRs), wearable devices, and biomedical data accelerates early disease identification and personalized therapeutic strategies, including those crucial for neonatal care and surgery. AI models trained on vast healthcare datasets can predict disease progression, recommend targeted therapies, and improve patient outcomes. Furthermore, natural language processing (NLP) enhances clinical documentation, reducing administrative burdens and improving efficiency in healthcare systems. Despite its potential, AI in precision medicine and neonatal surgery faces challenges, including data privacy concerns, model interpretability, and regulatory compliance. Ethical considerations, such as bias in AI models and equitable access to AI-driven healthcare, must be addressed to ensure responsible implementation. Additionally, integrating AI with traditional clinical workflows requires collaboration between healthcare professionals, data scientists, and policymakers. This survey provides a comprehensive analysis of AI applications in precision medicine, healthcare analysis, and neonatal surgery, highlighting key advancements, challenges, and future research directions. As AI continues to evolve, its role in revolutionizing healthcare will expand, paving the way for more efficient, accurate, and patient-centric medical practices. The findings of this survey aim to guide researchers, clinicians, and policymakers in leveraging AI for the next generation of precision healthcare, particularly in neonatal surgical interventions.

Hypoxia-inducible factor 1-alpha and lactate dehydrogenase-A axis in metabolic changes and aggression in esophageal squamous-cell carcinoma.

Esophageal squamous-cell carcinoma (ESCC) is a highly aggressive cancer, predominantly affecting populations in Eastern Asia and parts of Africa. Its pathogenesis is influenced by both genetic and environmental factors. Despite recent therapeutic advances, survival rates remain dismal, underscoring an urgent need for novel therapeutic targets. To investigate the role of hypoxia-inducible factor 1-alpha (HIF1A) in the progression of ESCC and its impact on the metabolic enzyme lactate dehydrogenase A (LDHA), which is crucial for the glycolytic pathway in hypoxic tumor environments. Utilizing transcriptomic data from multiple public databases, we analyzed differential gene expression and conducted gene ontology and transcription factor network analyses. The regulatory impact of HIF1A on LDHA was specifically examined through integrative analysis with HIF1A ChIP-seq data and confirmed via siRNA-mediated knockdown experiments in ESCC cell lines. Our findings reveal a significant upregulation of HIF1A in ESCC tissues, associated with poor prognosis. HIF1A directly regulates LDHA, enhancing glycolysis under hypoxic conditions and contributing to tumor aggressiveness. Knockdown of HIF1A in cell lines not only reduced LDHA expression but also altered key pathways related to cell cycle and apoptosis. The critical role of the HIF1A-LDHA axis in ESCC highlights its potential as a therapeutic target, underscoring the need for future clinical trials to validate the efficacy of HIF1A inhibitors in enhancing treatment outcomes.

Fetoplacental Hydrops: A Case of Recurrent Fetal Hydrops and Review of the Literature

Recurrent fetal hydrops is a severe condition with a generally poor prognosis. The causes of fetal hydrops are diverse and mainly classified as immunological or non-immunological, although genetic and metabolic factors contribute to the recurrent form. Maternal prognosis is also at risk due to the association of this condition with severe preeclampsia. For women with a history of pregnancy complicated by fetal hydrops, subsequent pregnancies require special monitoring to detect early ultrasound signs of recurrence. We report a case of recurrent hydrops fetalis, which represents the fourth episode. This case emphasizes the importance of etiological diagnosis, particularly genetic causes, to provide appropriate genetic counseling and prevent transmission to future generations.

Quantitative trait locus mapping and OsFLOq12 identification for rice grain hardness: towards improved rice flour for wheat substitution.

Recent shifts in consumer dietary preferences have led to a significant decline in rice consumption in Korea, resulting in surplus rice production. To address this issue, rice flour has been proposed as a substitute for wheat flour. However, the physical, chemical and structural differences between rice and wheat, particularly in grain hardness, pose challenges in using rice flour as an alternative. Understanding the genetic factors that influence rice grain hardness is crucial for improving the milling process and producing high-quality rice flour suitable for wheat flour substitution. In this study, various grain traits, including length, width, thickness, length-to-width ratio and hardness, were measured in a population of brown and milled rice. Quantitative trait locus (QTL) analysis revealed a significant association between grain hardness and thickness, with QTLs for grain hardness mapped on chromosomes 1 and 12 for brown and milled rice, respectively. A total of 20 candidate genes related to grain hardness were identified through QTL analysis. Among them, OsFLOq12 (LOC_Os12g43550) was identified as a key gene influencing grain hardness, which encodes a Ras small GTPase. Phenotypic analysis showed differences in endosperm appearance and particle size between lines with low and high grain hardness. The genetic analysis of OsFLOq12 revealed a single nucleotide polymorphism associated with grain hardness. This study provides valuable insights into the genetic background of grain hardness, offering a foundation for breeding rice varieties optimized for flour production as a viable substitute for wheat flour. © 2024 Society of Chemical Industry.

Biometry of the Mammary Gland: Implications for Livestock Breeding and Milk Production: A Review

The biometry of the mammary gland is a critical area of study that focuses on the measurement and analysis of its dimensions, structural changes and physiological variations across species and developmental stages. Various factors, including lactation stage, age, parity and genetic makeup significantly influence mammary gland morphology. These factors collectively contribute to the functional efficiency and productivity of the gland, particularly in livestock species where milk production is of paramount economic importance. Research indicates that the lactation stage plays a pivotal role in altering mammary gland size and structure, with substantial differences observed between early, mid and late lactation periods. Similarly, age and parity are crucial determinants, as older animals and those with higher parity exhibit distinct glandular characteristics, including changes in tissue composition and glandular volume. Genetic factors modulate these biometric parameters, influencing milk yield and gland resilience. This review consolidates data from multiple studies to provide a holistic understanding of mammary gland biometry, emphasizing its relevance to livestock management. Insights gained from this research can be utilized to enhance breeding programs to improve mammary gland function and milk production efficiency. By understanding the interplay of these factors, farmers and breeders can implement more targeted management practices that optimize animal welfare and productivity. Ultimately, the review aims to offer a comprehensive overview of mammary gland biometry, aiding in developing improved breeding and management strategies for livestock.

Captive environments reshape the compositions of carbohydrate active enzymes and virulence factors in wolf gut microbiome

Species in the family Canidae occupy different spatial ecological niches, and some (e.g., wolf) can be kept in zoos. The gut microbiome may differ among various wild and captive canids. Therefore, we compared the gut microbiomes of wild canids (wolf, red fox, and corsac fox) in the Hulun Lake area, captive wolves, and domestic dogs in different regions using metagenomic data. A random forest analysis revealed significant enrichment for bacterial species producing short-chain fatty acids and the thermogenesis pathway (ko04714) in the gut microbiome of wild wolf, potentially providing sufficient energy for adaptation to a wide range of spatial ecological niches. The significantly enriched bacterial species and functional pathways in the gut microbiome of corsac foxes were related to physiological stability and adaptation to arid environments. Alpha diversity of carbohydrate-active enzymes in the gut microbiome was higher in the red fox than in the corsac fox and wild wolf, which may be related to the abundance of plant seeds (containing carbohydrates) in their diets (red foxes inhabit seed-rich willow bosk habitats). However, the influence of host genetic factors cannot be excluded, and further experimental studies are needed to verify the study results. In addition, captive environments drove similarity in carbohydrate-active enzymes (CAZymes) and virulence factors (VFs) in the gut microbiomes of captive wolf and domestic dog, and increased the diversity of CAZymes and VFs in the gut microbiome of captive wolf. Increased VFs diversity may increase the pathogenic potential of the gut microbiome in captive wolves. Therefore, it is necessary to continue monitoring the health status of captive wolves and develop appropriate management strategies.