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Genetics and exercise: an introduction
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Claude Bouchard, Henning Wackerhage
Chromosomes have two arms and a central constriction which is termed the centromere. The short arm of a chromosome is denoted as p and the long arm as q. Each arm of the chromosome is subdivided into regions numbered consecutively from the centromere to the telomere which is the tip of each chromosome arm. Each band (i.e. the dark and light stripes of a chromosome seen in Figure 3.5) within a given region is identified by a number. With this nomenclature, it is possible to specify any chromosomal region by its “cytological address”. For example, chromosome 1 is composed of about 249 million (mega, M) DNA base pairs (Figure 3.6). 1p22 refers to chromosome 1, p arm, region 2, band 2. Since the sequence of the DNA bases of the entire human genome is now available, it is possible to specify a physical position on a given human chromosome in terms of the exact base number in a sequence ranging from one to millions. For instance, there are 4,300 genes encoded on chromosome 1. The gene KIF1B which encodes kinesin family member 1B codes for a motor protein that transports vesicles within cells. It is located on 1p36.22 and extends from 10.21 to 10.38 M bases of DNA.
Muscle Disorders
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Kourosh Rezania, Peter Pytel, Betty Soliven
Autosomal recessive disorder caused by impaired transport of free fatty acids into mitochondria. The abnormal gene maps to chromosome 1. Carnitine palmitoyltransferase II (CPT2) deficiency is the most common inherited cause of recurrent myoglobinuria.
Heterologous Pairing and Fertility in Humans
Published in Christopher B. Gillies, Fertility and Chromosome Pairing: Recent Studies in Plants and Animals, 2020
Two of the subfertile patients were chromosomally abnormal (Table 2), one carrying a t(9;20) reciprocal translocation, the other an inversion of chromosome 1. Synaptic progression of the XY bivalent in the translocation patient was comparable to the chromosomally normal subfertiles. Other features of chromosomal rearrangement leading to infertility will be dealt with later. The inversion-carrying patient suffered severe problems of XY synapsis. In 30% of the cells examined at the EM level, the sex chromosomes were unattached. A block with very little progression to the Type V nuclei occurred with excess numbers of Types I and II occurring. The detached nature of the sex bivalent will certainly contribute to infertility on the basis of the Miklos theory29 and problems of synapsis in inversions will be looked at in a later Section.
Testing differentially methylated regions through functional principal component analysis
Published in Journal of Applied Statistics, 2022
Mohamed Milad, Gayla R. Olbricht
To mimic methylation profile changes accurately, a simulation was constructed from the RRBS data set described above following the same approach as in M3D [13]. The regions (CpG clusters) were defined as follows: (1) CpG sites that covered at least 75% of samples were defined as frequently covered CpG sites and (2) a maximum distance of 100 base pairs to the nearest neighbor within a region was accepted. Using these criteria, only regions with at least 20 frequently covered CpG sites were used in the analysis [9]. The simulation study focused on the first 1000 regions on chromosome 1. Out of the 12 control samples in the RRBS data, 4 patients were randomly selected to use in the simulation study as controls. Four more replicates were simulated 100 times to be the testing group (i.e. cases). Of these, 250, 100 and 50 of the CpG clusters (predefined regions) were randomly selected to apply differential methylation changes. The replicates that acted as the testing group (cases) were simulated by first adding or subtracting random Poisson (λ =1) noise to the total number of reads at each cytosine. Uniform [−0.1, 0.1] random noise was added to cytosine methylation levels. The methylation level 13]. The degree of methylation level change was controlled by the parameter 13].
Animal models of systemic lupus erythematosus and their applications in drug discovery
Published in Expert Opinion on Drug Discovery, 2022
Yue Xin, Bo Zhang, Junpeng Zhao, Qianmei Liu, Haoyuan Yin, Qianjin Lu
Genetic studies on the NZM strains have contributed substantially to our understanding of the genetic predisposition of SLE and resulted in the generation of several transgenic SLE mouse models. Three susceptibility genes (Sle1, Sle2, and Sle3) have been identified in NZM 2410 mice and researchers have shown that they exert respective effects on SLE pathogenesis by constructing congenic strains (TC mice) carrying NZM 2410-derived Sle123 genes on a C57BL/6 background [34,35]. Sle1 is located on chromosome 1, is responsible for the loss of tolerance to nuclear antigens, and is the most essential gene for the initiation and lethality of SLE [36]. Sle2 on chromosome 4 lowers the activation threshold of B cells and is responsible for the expansion of autoreactive B cells, and Sle3 on chromosome 7 is related to the dysregulation of T cells and mediates nephritic damage [37]. Only animals coexpressing these transgenes exhibit full disease presentation and penetrance. The NZM 2328-derived susceptibility genes include Cgnz1, Agnz1 and Adnz1. The regions of Cgnz1 and Agnz1 overlap with Sle1 on chromosome 1, and Cgnz1 has a highly identical homologous region in the human genome. Adnz1 is related to antibody production [38].
Association between Fetal MTHFR A1298C (rs1801131) Polymorphism and Neural Tube Defects Risk: A Systematic Review and Meta-Analysis
Published in Fetal and Pediatric Pathology, 2022
Sara Soleimani-Jadidi, Bahare Meibodi, Atiyeh Javaheri, Razieh Sadat Tabatabaei, Amaneh Hadadan, Leila Zanbagh, Hajar Abbasi, Reza Bahrami, Seyed Reza Mirjalili, Mojgan Karimi-Zarchi, Hossein Neamatzadeh
The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) plays an important role in the folate metabolism pathway and regulates the intracellular folate pool for synthesis and methylation of DNA folate metabolism [15]. Among genetic factors, variations in MTHFR gene have been assessed as potential risk factors in development of NTDs. The best-characterized MTHFR genetic mutation 677 C > T is associated with a 2-4 fold increased risk of NTDs if the patient is homozygous for this mutation [16]. It is suggested that folate transport may be affected by immunological responses and maternal autoantibodies that bind to the folate receptor, blocking the intracellular uptake of folate, which may then lead to NTDs [17]. The human gene has been mapped to the telomeric region of the chromosome 1 (1p36.3), consists of 11 exons, and spans a 2 kbp coding region [18–20]. The MTHFR A1298C polymorphism is an A to C transition at base pair 1298, occurs in exon 7 resulting in the Glu to valine substitution at position 429 of the protein at the C- terminal regulatory domain of the protein and decreases the enzyme activity [21, 22]. There have been several reports attempting to prove the association between MTHFR A1298C polymorphism and NTDs among different populations, but the results are controversial. Given that the results of previous studies remain inconclusive and controversial, we conducted the current meta-analysis to further evaluate the correlation between MTHFR A1298C (rs1801131) and the susceptibility to NTDs.