scholarly journals Diet effects on mouse sperm: a warning for recombination studies

2021 ◽  
Author(s):  
Elena de la Casa-Esperon ◽  
Estefania San Martin Perez ◽  
Angela Belmonte Tebar ◽  
Syong Hyun Nam-Cha ◽  
Ana Josefa Soler Valls ◽  
...  

Meiotic recombination is a critical process for sexually reproducing organisms. This exchange of genetic information between homologous chromosomes during meiosis is important not only because it generates genetic diversity, but also because it is often required for proper chromosome segregation. Consequently, the frequency and distribution of crossovers are tightly controlled to ensure fertility and offspring viability. However, in many systems it has been shown that environmental factors can alter the frequency of crossover events. Two studies in flies and yeast point to nutritional status affecting the frequency of crossing over. However, this question remains unexplored in mammals. Here we test how crossover frequency varies in response to diet in Mus musculus males. We use immunohistochemistry to estimate crossover frequency in multiple genotypes under two diet treatments. Our results indicate that while crossover frequency was unaffected by diet in some strains, other strains were sensitive even to small composition changes between two common laboratory chows. Therefore, recombination is both resistant and sensitive to certain dietary changes in a strain-dependent manner and, hence, this response is genetically determined. Our study is the first to report a nutrition effect on genome-wide levels of recombination. Moreover, our work highlights the importance of controlling diet in recombination studies and may point to diet as a potential source of variability among studies, which is relevant for reproducibility.

Genetics ◽  
2021 ◽  
Author(s):  
Angela Belmonte Tebar ◽  
Estefania San Martin Perez ◽  
Syong Hyun Nam-Cha ◽  
Ana Josefa Soler Valls ◽  
Nadia D Singh ◽  
...  

Abstract Meiotic recombination is a critical process for sexually reproducing organisms. This exchange of genetic information between homologous chromosomes during meiosis is important not only because it generates genetic diversity, but also because it is often required for proper chromosome segregation. Consequently, the frequency and distribution of crossovers are tightly controlled to ensure fertility and offspring viability. However, in many systems it has been shown that environmental factors can alter the frequency of crossover events. Two studies in flies and yeast point to nutritional status affecting the frequency of crossing over. However, this question remains unexplored in mammals. Here we test how crossover frequency varies in response to diet in Mus musculus males. We use immunohistochemistry to estimate crossover frequency in multiple genotypes under two diet treatments. Our results indicate that while crossover frequency was unaffected by diet in some strains, other strains were sensitive even to small composition changes between two common laboratory chows. Therefore, recombination is both resistant and sensitive to certain dietary changes in a strain-dependent manner and, hence, this response is genetically determined. Our study is the first to report a nutrition effect on genome-wide levels of recombination. Moreover, our work highlights the importance of controlling diet in recombination studies and may point to diet as a potential source of variability among studies, which is relevant for reproducibility.


Author(s):  
Guzide Satir Basaran ◽  
Yagut Akbarova ◽  
Kezban Korkmaz ◽  
Kursad Unluhizarci ◽  
Francois Cuzin ◽  
...  

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Antt Htet Wai ◽  
Muhammad Waseem ◽  
A B M Mahbub Morshed Khan ◽  
Ujjal Kumar Nath ◽  
Do Jin Lee ◽  
...  

Protein disulfide isomerases (PDI) and PDI-like proteins catalyze the formation and isomerization of protein disulfide bonds in the endoplasmic reticulum and prevent the buildup of misfolded proteins under abiotic stress conditions. In the present study, we conducted the first comprehensive genome-wide exploration of the PDI gene family in tomato (Solanum lycopersicum L.). We identified 19 tomato PDI genes that were unevenly distributed on 8 of the 12 tomato chromosomes, with segmental duplications detected for 3 paralogous gene pairs. Expression profiling of the PDI genes revealed that most of them were differentially expressed across different organs and developmental stages of the fruit. Furthermore, most of the PDI genes were highly induced by heat, salt, and abscisic acid (ABA) treatments, while relatively few of the genes were induced by cold and nutrient and water deficit (NWD) stresses. The predominant expression of SlPDI1-1, SlPDI1-3, SlPDI1-4, SlPDI2-1, SlPDI4-1, and SlPDI5-1 in response to abiotic stress and ABA treatment suggested they play regulatory roles in abiotic stress tolerance in tomato in an ABA-dependent manner. Our results provide new insight into the structure and function of PDI genes and will be helpful for the selection of candidate genes involved in fruit development and abiotic stress tolerance in tomato.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Su Yon Jung ◽  
Jeanette C. Papp ◽  
Eric M. Sobel ◽  
Matteo Pellegrini ◽  
Herbert Yu ◽  
...  

AbstractMolecular and genetic immune-related pathways connected to breast cancer and lifestyles in postmenopausal women are not fully characterized. In this study, we explored the role of pro-inflammatory cytokines such as C-reactive protein (CRP) and interleukin-6 (IL-6) in those pathways at the genome-wide level. With single-nucleotide polymorphisms (SNPs) in the biomarkers and lifestyles together, we further constructed risk profiles to improve predictability for breast cancer. Our earlier genome-wide association gene-environment interaction study used large cohort data from the Women’s Health Initiative Database for Genotypes and Phenotypes Study and identified 88 SNPs associated with CRP and IL-6. For this study, we added an additional 68 SNPs from previous GWA studies, and together with 48 selected lifestyles, evaluated for the association with breast cancer risk via a 2-stage multimodal random survival forest and generalized multifactor dimensionality reduction methods. Overall and in obesity strata (by body mass index, waist, waist-to-hip ratio, exercise, and dietary fat intake), we identified the most predictive genetic and lifestyle variables. Two SNPs (SALL1 rs10521222 and HLA-DQA1 rs9271608) and lifestyles, including alcohol intake, lifetime cumulative exposure to estrogen, and overall and visceral obesity, are the most common and strongest predictive markers for breast cancer across the analyses. The risk profile that combined those variables presented their synergistic effect on the increased breast cancer risk in a gene–lifestyle dose-dependent manner. Our study may contribute to improved predictability for breast cancer and suggest potential interventions for the women with the risk genotypes and lifestyles to reduce their breast cancer risk.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Said ◽  
Y.J Van De Vegte ◽  
N Verweij ◽  
P Van Der Harst

Abstract Background Caffeine is the most widely consumed psychostimulant and is associated with lower risk of coronary artery disease (CAD) and type 2 diabetes (T2D). However, whether these associations are causal remains unknown. Objectives This study aimed to identify genetic variants associated with caffeine intake, and to investigate possible causal links between genetically determined caffeine intake and CAD or T2D. Additionally, we aimed to replicate previous observational findings between caffeine intake and CAD or T2D. Methods Genome wide associated studies (GWAS) were performed on caffeine intake from coffee, tea or both in 407,072 UK Biobank participants. Identified variants were used in a two-sample Mendelian randomization (MR) approach to investigate evidence for causal links between caffeine intake and CAD in CARDIoGRAMplusC4D (60,801 cases; 123,504 controls) or T2D in DIAGRAM (26,676 cases; 132,532 controls). Observational associations were tested within UK Biobank using Cox regression analyses. Results Moderate observational caffeine intakes from coffee or tea were associated with lower risks of CAD or T2D compared to no or high intake, with the lowest risks at intakes of 120–180 mg/day from coffee for CAD (HR=0.77 [95% CI: 0.73–0.82; P<1e-16]), and 300–360 mg/day for T2D (HR=0.76 [95% CI: 0.67–0.86]; P=1.57e-5). GWAS identified 51 novel genetic loci associated with caffeine intake, enriched for central nervous system genes. In contrast to observational analyses, MR analyses in CARDIoGRAMplusC4D and DIAGRAM yielded no evidence for causal links between caffeine intake and the development of CAD or T2D. Conclusions MR analyses indicate caffeine intake might not protect against CAD or T2D, despite protective associations in observational analyses. Manhattan_plot_CaffeineIntake Funding Acknowledgement Type of funding source: None


Acta Tropica ◽  
2021 ◽  
pp. 106127
Author(s):  
Ester Rose ◽  
Aline Moraes ◽  
Tatiana Shiroma ◽  
Nadjar Nitz ◽  
Ana de Cássia Rosa ◽  
...  

2004 ◽  
Vol 13 (7) ◽  
pp. 1927-1932 ◽  
Author(s):  
Wojciech Dzwolak ◽  
Vytautas Smirnovas ◽  
Ralf Jansen ◽  
Roland Winter

2009 ◽  
Vol 191 (13) ◽  
pp. 4082-4096 ◽  
Author(s):  
Nicholas J. Shikuma ◽  
Fitnat H. Yildiz

ABSTRACT Vibrio cholerae is a facultative human pathogen. In its aquatic habitat and as it passes through the digestive tract, V. cholerae must cope with fluctuations in salinity. We analyzed the genome-wide transcriptional profile of V. cholerae grown at different NaCl concentrations and determined that the expression of compatible solute biosynthesis and transporter genes, virulence genes, and genes involved in adhesion and biofilm formation is differentially regulated. We determined that salinity modulates biofilm formation, and this response was mediated through the transcriptional regulators VpsR and VpsT. Additionally, a transcriptional regulator controlling an osmolarity adaptation response was identified. This regulator, OscR (osmolarity controlled regulator), was found to modulate the transcription of genes involved in biofilm matrix production and motility in a salinity-dependent manner. oscR mutants were less motile and exhibited enhanced biofilm formation only under low-salt conditions.


Author(s):  
Miriam N. Ojima ◽  
Yuya Asao ◽  
Aruto Nakajima ◽  
Toshihiko Katoh ◽  
Motomitsu Kitaoka ◽  
...  

Human milk oligosaccharides (HMOs), which are natural bifidogenic prebiotics, were recently commercialized to fortify formula milk. However, HMO-assimilation phenotypes of bifidobacteria vary by species and strain, which has not been fully linked to strain genotype. We have recently shown that specialized uptake systems, particularly for the internalization of major HMOs (fucosyllactose (FL)), are associated with the formation of a bifidobacteria-rich gut microbial community. Phylogenetic analysis has revealed that FL transporters have diversified into two clades harboring four clusters within the Bifidobacterium genus, but the underpinning functional diversity associated with this divergence remains underexplored. In this study, we examined the HMO-consumption phenotypes of two bifidobacterial species, Bifidobacterium catenulatum subspecies kashiwanohense and Bifidobacterium pseudocatenulatum , which both possess FL binding proteins that belong to phylogenetic clusters with unknown specificities. Growth assays, heterologous gene expression experiments, and HMO-consumption analysis showed that the FL transporter type from B. catenulatum subspecies kashiwanohense JCM 15439 T conferred a novel HMO-uptake pattern that includes the complex fucosylated HMOs (lacto- N- fucopentaose II and lacto- N- difucohexaose I/II). Further genomic landscape analyses of FL transporter-positive bifidobacterial strains revealed that H-antigen or Lewis antigen-specific fucosidase gene(s) and FL transporter specificities were largely aligned. These results suggest that bifidobacteria have acquired FL transporters along with the corresponding gene sets necessary to utilize the imported HMOs. Our results provide insight into the species- and strain-dependent adaptation strategies of bifidobacteria to HMO-rich environments. Importance The gut of breastfed infants is generally dominated by health-promoting bifidobacteria. Human milk oligosaccharides (HMOs) from breastmilk selectively promote the growth of specific taxa such as bifidobacteria, thus forming an HMO-mediated, host-microbe symbiosis. While the co-evolution of humans and bifidobacteria has been proposed, the underpinning adaptive strategies employed by bifidobacteria require further research. Here, we analyzed the divergence of the critical fucosyllactose (FL) HMO transporter within Bifidobacterium . We have shown that the diversification of the solute-binding proteins of the FL-transporter led to uptake specificities of fucosylated sugars ranging from simple trisaccharides to complex hexasaccharides. This transporter and the congruent acquisition of the necessary intracellular enzymes allows for bifidobacteria to import different types of HMOs in a predictable and strain-dependent manner. These findings explain the adaptation and proliferation of bifidobacteria in the competitive and HMO-rich infant gut environment and enable accurate specificity annotation of transporters from metagenomic data.


Author(s):  
Jacqueline R. Phan ◽  
Dung M. Do ◽  
Minh Chau Truong ◽  
Connie Ngo ◽  
Julian H. Phan ◽  
...  

Clostridioides difficile infection (CDI) is the major identifiable cause of antibiotic-associated diarrhea. The emergence of hypervirulent C. difficile strains has led to increases in both hospital- and community-acquired CDI. Furthermore, CDI relapse from hypervirulent strains can reach up to 25%. Thus, standard treatments are rendered less effective, making new methods of prevention and treatment more critical. Previously, the bile salt analog CamSA was shown to inhibit spore germination in vitro and protect mice and hamsters from C. difficile strain 630. Here, we show that CamSA was less active at preventing spore germination of other C. difficile ribotypes, including the hypervirulent strain R20291. Strain-specific in vitro germination activity of CamSA correlated with its ability to prevent CDI in mice. Additional bile salt analogs were screened for in vitro germination inhibition activity against strain R20291, and the most active compounds were tested against other strains. An aniline-substituted bile salt analog, (CaPA), was found to be a better anti-germinant than CamSA against eight different C. difficile strains. In addition, CaPA was capable of reducing, delaying, or preventing murine CDI signs in all strains tested. CaPA-treated mice showed no obvious toxicity and showed minor effects on their gut microbiome. CaPA’s efficacy was further confirmed by its ability to prevent CDI in hamsters infected with strain 630. These data suggest that C. difficile spores respond to germination inhibitors in a strain-dependent manner. However, careful screening can identify anti-germinants with broad CDI prophylaxis activity.


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