Research Article

Table of Contents | Genet. Mol. Res. 2022 (2)

Displaying 1 - 5 of 5
Research Article

Wheat is considered a basic cereal for civilization with great economic importance for world agriculture. Currently, wheat is planted in the south, southeast and midwest regions of Brazil. Brazilian consumption of wheat will grow in the coming years due to population increase, which will require developing new cultivars for non-tradtional regions. We investigated commercial wheat genotypes grown at various sowing dates in a region with high temperature conditions. The experiment was conducted during the two summer and two autumn seasons. Sowings were March 10, March 20, April 1 and April 10. The agronomic traits (grain yield, plant height, spike size, total spikelets per spike and fertile spikelets per spike) for four commercial genotypes were evaluated. The experimental design was randomized blocks in a factorial scheme, corresponding to four genotypes, four sowing seasons and two years of cultivation. The second sowing year gave the best performance for the genotypes. Genotypes BR 18 and BRS 404 gave superior agronomic performance, standing out in the third and fourth sowing dates, under these culture conditions.

Genet. Mol. Res. 21(2): GMR18993
DOI: 10.4238/gmr18993
Research Article

X chromosome inactivation (XCI) compensates for the imbalance in gene expression between sexes. In mice, it is well established that the long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is essential for initiating XCI. The most well-known antisense transcript of the mouse XIST locus is TSIX, a negative modulator of XIST. However, in cattle, these events are not yet well established. In this study, we characterized the patterns of strand-specific transcription along the XIST locus in bovine fetal placenta, since understanding the regulation of gene expression in the placenta and of the transcripts involved in XCI in order to minimize embryonic and fetal losses due to the use of assisted reproduction techniques (ARTs) is key for livestock production. Sense transcription was detected throughout the XIST locus in male and female, and antisense transcription was detected in exon 1 of female fetal cotyledons. The sense transcripts may be lncRNA XIST, while the antisense transcript identified in exon 1 is not TSIX, but rather other uncharacterized RNAs. Moreover, our results show the relevance of taking into account the possibility of antisense expression for gene expression studies, especially in non-coding RNA or pseudogenes loci, where transcription from the two DNA strands is not rare. Taken together, the results show the importance of characterization as an aid to a better understanding of XCI in cattle, considering that epigenetic reprogramming can be impaired in cattle by the use of ARTs.

Genet. Mol. Res. 21(2): GMR19039
DOI: 10.4238/gmr19039
Research Article

Genome mapping is a simplified representation of molecular markers or nucleotide sequences in chromosomes; developing accurate and dense maps is crucial for marker-assisted selection. We developed and compared genetic linkage maps obtained using JoinMap 4.0 and GACD with a physical map obtained using BLAST analysis based on Eucalyptus SNPs transferred to guava, Psidium guajava (Myrtaceae) - to serve as a reference for trait mapping in this crop. Genotyping was conducted on 112 individuals from an experimental cross between a well-known commercial cultivar and an exotic genotype (Pedro Sato × Purple guava), using the Euchip60K SNP chip, version 2.0 (72,202 SNPs); 79% of the SNPs were monomorphic. After data filtering, 1120 markers were used for map construction. The JoinMap 4.0 linkage map had 203 markers, spanning 1405.2 cM, with an average marker distance of 7.7 cM. The GACD linkage map had 186 markers and spanned 1392.7 cM, with an average marker distance of 8.8 cM. JoinMap and GACD disagreed on the estimated distances and SNP ordering. GACD showed a greater limitation than JoinMap 4.0 as it ordered markers according to their parental origin. The physical map developed using BLAST consisted of 694 hits (e-values from 8xE-10 to 1.15xE-26), spanning 434.88 Mb, with an average marker interval of 0.62 Mb. Both linkage maps showed linkage groups with segments from several chromosomes compared to the physical map, indicating limitations. These results highlight the effectiveness of physical mapping through BLAST to overcome linkage mapping limitations, such as in marker grouping and ordering. The physical maps proposed here can serve as a reference for mapping and QTL estimates in guava.

Genet. Mol. Res. 21(2): GMR19033
DOI: 10.4238/gmr19033
Research Article

This study aimed to examine the effects of curcumin, a phytochemical antioxidant, on the treatment and care of diabetic nephropathy and to contribute to alternative treatment strategies for diabetes. Male Wistar albino rats (8–10 weeks old) were divided into five groups of seven. Experimental diabetes was induced in all rats except for those in Group 1 (placebo group) by administration of 110 mg/kg nicotinamide, followed by intraperitoneal administration (after 15 min) of 55 mg/kg streptozotocin. Groups 1, 3, 4, and 5 were treated with 0.1 ml normal saline (0.9% NaCl), 150mg/kg/day metformin, 10 mg/kg/day glycazide (diamicron), and 200 mg/kg/day curcumin, respectively. Group 2 did not receive any treatment. Kidney tissues of rats were collected for histopathological examination.  There were no significant differences in the kidney dimensions of the rats. In the histopathological evaluation of kidney tissues with diabetic nephropathy, glomerular congestion and destruction were observed. Rats treated with curcumin had significantly less kidney damage, based on histopathological analysis, than those treated with the diabetes drugs.  We conclude that curcumin has protective effects in kidneys due to its antioxidant properties. It has potential for use, in addition to antidiabetic drugs, for diabetes treatment.

Genet. Mol. Res. 21(2): GMR19026
Research Article

We investigated single nucleotide polymorphisms of four genes (calpain (CAPN-9 and CAPN-14), calpastatin – CAST, diacylglycerol acyltransferase – DGAT, and leptin - LEP) that are related to beef quality, and we examined changes in the synthesis of proteins that they encode in Nellore cattle. Samples from 95 adult males of commercial origin were analyzed. Genomic DNA was extracted from the longissimus dorsi (sirloin) muscle tissue, identified with PCR-single-stranded conformation polymorphism analysis. For each different pattern identified, the products were sent for sequencing and analyzed using sequence scanner software. The data were analyzed by determining the absolute and relative frequencies of the polymorphisms identified in each gene. For the CAPN-9 gene, sequencing showed five polymorphisms (G/A, T/A, T/C, T/C, and A/G), of which two involved amino acid substitutions (c.5861G>A and c.5498A>G). Sequencing of the CAPN-14 gene revealed four polymorphisms (A/C, G/A, T/C, and C/G), with two involving amino acid substitutions (c.11054 T>C and c.11161C>G). Sequencing of the CAST-5 gene revealed five polymorphisms (C/T, T/C, C/A, C/A, and G/T), four of which involved amino acid substitutions (c.29919C>T, c.29963A>C, c.29978C>A, and c.30019G>T). Sequencing of the DGAT gene revealed six polymorphisms (T/A, G/A, A/T, G/C, A/G, and G/A), four of which involved amino acid substitutions (c.11730A>T, c.11809G>C, c.11858A>G, and c.11927G>A). Sequencing of the LEP gene revealed three polymorphisms (C/T, C/T and T/C), with one involving an amino acid substitution (c.14962T>G). These genes   had a large number of polymorphisms resulting in amino acid differences in Nellore Cattle. These polymorphisms involving amino acid changes may promote functional changes in beef characteristics of Nellore cattle given that these genes are associated with beef quality parameters.

Genet. Mol. Res. 21(2): GMR18983
DOI: 10.4238/gmr18983