Distribution of polymorphic forms at the porcine GH locus in a population of day-10 pig embryos

Abstract. The present study describes an analysis of genotype and allele distribution at the porcine GH locus among day-10 pig embryos. Embryos were collected post mortem from 6 crossbred (Danish Landrace × Yorkshire) sows inseminated with mixed Duroc semen and individually frozen for later analysis. After extraction, DNA was subjected to PCR amplification and restriction analysis with Msp I and Hae II enzymes. The genotype frequencies were: Msp I CD 0.17, DD 0.83; and Hae II AA 0.33, AB 0.58; and BB 0.09. The Msp I CC genotype was not found among analysed embryos. To our knowledge, this is the first report on the genotype and allele distribution at the GH locus among early pig embryos

Cathepsin mRNA level in bovine cumulus cells fails to be a good marker of oocyte quality

Cathepsins (CTS) are lysosomal cysteine proteinases, of which elevated transcript content is attributed to the reduced quality of oocytes. The aim of this study was to investigate whether transcript content of three CTS genes in cumulus cells (CC) may be related to oocyte quality. The relationships between mRNA content of CTS genes in CC, the fatty acids profile in follicular fluid (FF) and selected quality traits of the corresponding oocyte (COC morphology, follicle diameter, mtDNA copy number) were investigated. Although an increased RA of the CTSB and the CTSK genes was accompanied by inferior COC morphology, it was also correlated with a higher mtDNA copy number in the oocyte and an increased content of C18.3n3 and n3 in FF. The last two traits were attributed to better quality oocytes, which contrasts with the high RA of the CTS genes. In conclusion, elevated transcript levels of CTS genes within CC are of limited value as an indicator of reduced quality in bovine oocytes. We suggest that the possible reason for the ambiguity of the obtained data could be the origin of cumulus cells within the COC, which may prove to be crucial for this type of studies

In vitro maturation and fertilisation of bovine oocytes in relation to GH gene polymorphism (Leu/Val)

The present study describes the analysis of the associations between the growth hormone gene polymorphism (Leu/Val) and oocyte maturation and in vitro fertilisation in cattle. Two independent experiments were carried out. In the first one, oocytes were collected from 49 single ovaries, matured in vitro, measured and cytogenetically analysed. One ovary was considered as a donor. The procedure of the donor's genotyping at the GH locus was based on DNA extracted from the granulosa cells. The GH genotype did not influence the oocyte diameter nor the number of oocytes collected, which were selected for maturation and matured. An unreduced chromosome number was found in 8.8% of the cells at the second metaphase stage and 42.9% of the donors. This anomaly was observed in all genotype groups with a higher frequency in the VV cows ($P < 0.01$). In the second experiment, the oocytes collected from 72 single ovaries were matured and fertilised in vitro. The GH genotype of a donor did not influence the number of zygotes cleaved on day-2. It has to be mentioned, that due to the low frequency of the VV genotype (0.03), the results of the present study should be treated as preliminary and need further analysis

Size distribution of <i>Sus scrofa</i> piRNA isolated from testes (<b>A</b>) and ovaries (<b>B</b>).

<p>Size distribution of <i>Sus scrofa</i> piRNA isolated from testes (<b>A</b>) and ovaries (<b>B</b>).</p

ORIGINAL RESEARCH Low incidence of chromosome aberrations in spermatozoa of fertile boars

Chromosomal imbalance in gametes and embryos is one of the factors contributing to early embryonic mortality. Although the rate of chromosomally abnormal sperm cells is low and usually does not exceed 1%, there is no clear indication of fertilizing potential of such gametes. The aim of the experiment was to investigate the type and incidence of numerical chromosomal aberrations in spermatozoa produced by fertile boars used in artificial insemination (AI). We used the protocol of fluorescent in situ hybridization (FISH) on sperm interphase nuclei with molecular probes for porcine chromosome pairs 1 and 10. Altogether 12 348 sperm cells were examined. Disomy was observed in spermatozoa of all seven AI boars whereas only one diploid cell was identified in all screened sperm cells. The average rate of chromosomally unbalanced sperm was 0.105 % (13/12 348) with an inter-individual variation from 0.048 % to 0.194%. Among abnormal sperm cells, both disomy (0.097%) and diploidy (0.008%) were detected. Nullisomy was not included into calculations. The estimated aneuploidy rate calculated by doubling the number of disomic cells was 0.194%. Chromosome pair 10 was significantl

Differences in aminoacid sequences of <i>Sus scrofa</i> Piwi proteins.

<p>Differences in aminoacid sequences of <i>Sus scrofa</i> Piwi proteins.</p

piRNA class of ∼30-nt small RNA identified in <i>Sus scrofa</i> testes and ovaries.

<p>RNA enriched with low-molecular-weight RNA was isolated from: <b>A</b> - testes of neonatal (1) and adult (2) male; <b>B</b> – ovaries of neonatal (1) and cyclic (2) females; <b>C</b> – ovaries of three-month-old (1), prebupertal (2) and pubertal (3) pigs. Approximately 8 µg of low-molecular-weight RNA was loaded on 15% acrylamide gel and stained using SYBR-gold. M – marker; set of synthetic RNA fragments available in the laboratory.</p