Study of inter- and intra-individual variation of meiotic segregation patterns in t(3;15)(q27;q13) boars.

Constitutional chromosomal rearrangements are relatively frequent genetic anomalies in both man and pigs. Among them, reciprocal translocations, present a specific meiotic segregation pattern. The potential "individual" effect of the t(3;15)(q27,q13) translocation was studied using SpermFISH to analyze the meiotic segregation patterns of three boars carrying this rearrangement. Three samples were taken at different times from one of these boars to analyze a potential "time" effect. No "time" or "individual" effect was found in this study. These results should allow more efficient management of certain reciprocal translocations in pig populations but need to be completed by the study of other kinds of chromosomal rearrangements.

Meiotic segregation analysis in cows carrying the t(1;29) Robertsonian translocation.

Heterozygous carriers of Robertsonian translocations generally have a normal phenotype but present reproductive failure. In cattle, the t(1;29) Robertsonian translocation is very common and carriers show a 3-5% decrease in fertility. Some data suggest that female carriers have a higher decrease than male carriers but no direct studies of the chromosome content of oocytes from a t(1;29) carrier cow have been performed so far. Four heterozygous carrier cows underwent hormonal stimulations and follicles punctions and about 800 oocytes were matured in vitro. Six hundred metaphase II preparations were obtained and analysed by fluorescent in situ hybridization with bovine chromosome 1 and 29 painting probes. Proportions of different kinds of oocytes were assessed: 74.11% (292/394) were normal and balanced, 4.06% (16/394) unbalanced and 21.83% (86/394) diploid. For all cows, the number of normal oocytes was not significantly different from the number of translocated oocytes but the diploidy and unbalanced rate were significantly different between them. As found in bulls, the meiotic segregation pattern in cows has shown a preponderance of alternate products. However, the frequency of unbalanced gametes determined in females (4.06%) was significantly higher than the frequency observed in males (2.76%). The divergence in the rate of diploid gametes (0.04% vs. 21.83%) is mainly explained by the difference between males and females.

Meiotic studies in an azoospermic boar carrying a Y;14 translocation.

A reciprocal translocation between the q arm of the Y chromosome and the q arm of chromosome 14 was identified in a young, phenotypically normal boar presenting azoospermia. Testicular biopsies were analyzed by classical histological and immunolocalization techniques, and by fluorescence in situ hybridization. Meiotic pairing analysis of 85 pachytene spreads showed the presence of an open structure corresponding to a quadrivalent formed by chromosomes 14, X, and the derivative chromosomes 14 and Y in 84.7% of the cases. In the remaining cases (15.3%), a 'trivalent plus univalent' configuration was observed. Immunolocalization of gammaH2AX revealed the presence of this modified histone in the chromatin domains of unsynapsed segments (centromeric region of chromosome 14) and spreading of the gammaH2AX signal from the XY body throughout chromosome 14 in 7.05% of the cells analyzed. The potential causes of the observed infertility, i.e. activation of meiotic checkpoints and/or silencing of genes necessary for the progression of meiosis, are discussed.

Sperm nuclei analysis of 1/29 Robertsonian translocation carrier bulls using fluorescence in situ hybridization.

In 1964, Gustavsson and Rockborn first described the 1/29 Robertsonian translocation in cattle. Since then, several studies have demonstrated the negative effect of this particular chromosomal rearrangement on the fertility of carrier animals. During the last decade, meiotic segregation patterns have been studied on human males carrying balanced translocations using FISH on decondensed sperm nuclei. In this work, we have applied the 'Sperm-FISH' technique to determine the chromosomal content of spermatozoa from two bulls heterozygous for the 1/29 translocation and one normal bull (control). 5425 and 2702 sperm nuclei were scored, respectively, for the two heterozygous bulls, using whole chromosome painting probes of chromosomes 1 and 29. Very similar proportions of normal (or balanced) spermatozoa resulting from alternate segregation were observed (97.42% and 96.78%). For both heterozygous bulls, the proportions of nullisomic and disomic spermatozoa did not follow the theoretical 1:1 ratio. Indeed, proportions of nullisomic spermatozoa were higher than those of disomic sperma tozoa (1.40% vs 0.09% (bull 1) and 1.29% vs 0.15% (bull 2) for BTA1, and 0.65% vs 0.40% (bull 1) and 1.11% vs 0.63% (bull 2) for BTA29). The average frequencies of disomic and diploid spermatozoa in the normal bull were 0.11% and 0.05%, respectively.

Cleft palate associated with an unbalanced karyotype in piglets sired by a heterozygous carrier boar with a balanced constitutional reciprocal translocation.

The progeny of a commercial (Landrace x Duroc) x Large White boar contained a number of piglets with cleft palates. Chromosomal analyses of five affected piglets showed that they all had an identical unbalanced karyotype with partial monosomy of chromosome 16 and partial trisomy of chromosome 3, whereas the normal piglets in the litters had balanced karyotypes. The chromosomal imbalance was the direct result of a constitutional balanced reciprocal translocation carried by their heterozygote sire, described, according to the standard nomenclature, as t(3;16)(q23;q22).

Chromosomal abnormalities in hypoprolific boars.

Four new chromosomal rearrangements are reported in the domestic pig: 3 reciprocal translocations, rcp(4;12)(p13;q13) in a crossbred boar, rcp(1;7)(q17;q26) in a Large White purebred boar, rcp(1;6)(q17;q35) in a purebred synthetic paternal line boar, and a pericentric inversion inv(2)(p13q11) in a crossbred boar. The 1/7 reciprocal translocation and the pericentric inversion were detected in animals that had sired small litters. The effect of the 1/7 translocation was accurately determined: -4.5 piglets born per litter, i.e. -36%. Both the 1/6 and 1/7 reciprocal translocations were of maternal origin. All the chromosomal rearrangements were highlighted using GTG and/or RBG banding techniques. Chromosome painting experiments were also carried out to confirm the proposed hypotheses for the three reciprocal translocations.

A new reciprocal translocation in a subfertile bull.

Three bulls of the Montbéliarde breed that exhibited fertility rates lower than 30% following more than 400 artificial inseminations were examined. Semen quality (sperm motility and morphology) from these bulls was normal. Fertilizing ability estimated from in vitro embryo production results was studied for two of them. In vitro production rate was very low for one bull (A) and normal for the other (B). Cytogenetic analyses were carried out on the three bulls using chromosome banding techniques. These analyses revealed a reciprocal translocation (12;17)(q22;q14) in bull B. Based on family analyses, the hypothesis of a de novo origin of this rearrangement is proposed.

Five new cases of reciprocal translocation in the domestic pig.

Five new cases of reciprocal translocation in the domestic pig are described. Three of them, rep(3;5)(p1.3;q2.3), rep(6;13)(p1.5;q4.1) and rep(13;17)(q4.1;q1.1) were found in boars with decreased litter size. The remaining two were identified in animals karyotyped before reproduction: a young boar, rep(4;6)(q2.1;q2.8), and a gilt, rep(2;14)(q1.3;q2.7). A parental origin by inheritance of the translocations was established in cases 1, 4, and 5. A decrease in prolificacy of 43% and 34% was estimated in cases 1 and 3, respectively.

Nine new cases of reciprocal translocation in the domestic pig (Sus scrofa domestica L.).

Nine pigs with decreased litter size or sired by boars with decreased litter size were found to be reciprocal translocation carriers. Four Large White animals (two females and two males) demonstrated translocations involving chromosomes 1 and 9 (1p-;9p+), 11 and 13 (11q+;13q-), 3 and 13 (3;13)(p1.5;q3.1), and 15 and 17 (15;17)(q1.3;q2.1). Two Large White x Pietrain terminal boars demonstrated translocations involving chromosomes 11 and 16 (11;16)(p1.4;q1.4), and 6 and 14 (6;14)(q2.7;q2.1). The (9;15)(p2.4;q1.3) and (6;16)(q1.1;q1.1) translocations were found in a Large White x French Landrace boar, and in a commercial male line boar with decreased litter size, respectively. A Gascon breed boar with reduced prolificacy also had an abnormal karyotype, namely 38 XY, rcp(1;6)(q1.2;q2.2). Reduction in prolificacy was estimated accurately in cases 3, 5, 6, 7, and 9 (35%, 30%, 35%, 41%, and 56%, respectively). Rcp(1;6)(q1.2;q2.2) and rcp(6;16)(q1.1;q1.1) seemed to have been of de novo origin.

Characterization of reciprocal translocations in pigs using dual-colour chromosome painting and primed in situ DNA labelling.

We report the use of dual-colour chromosome painting to determine the exact nature of certain chromosome rearrangements observed in the pig (Sus scrofa domestica). The chromosomal abnormalities were detected by GTG- and RBG-banding techniques. The initially proposed interpretations were: (1) rcp(6;13)(p1.5;q4.1); (2) rcp(11;16)(p1.4;q1.4); (3) rcp(6;16)(p1.1;q1.1); (4) rcp(13;17)(q4.1;q1.1); (5) rcp(6;14)(q2.7;q2.1); (6) rcp(3;5)(p1.3;q2.3); (7) rcp(2; 14)(q1.3;q2.7); (8) rcp(15;17)(q1.3;q2.1). Hybridizations were carried out with biotin- and digoxigenin-labelled probes obtained by priming authorizing random mismatches polymerase chain reaction (PARM-PCR) amplification of porcine flow-sorted chromosomes. In some cases, i.e. (1), (4), (5), (6), (7) and (8), the fluorescence in situ hybridization (FISH) results allowed confirmation of the interpretations proposed with classical cytogenetic methods. Chromosome painting proved the reciprocity of the translocation in cases (1), (6) and (8), whereas modifications of the formula were proposed for case (2). Primed in situ DNA labelling (PRINS) experiments have also been carried out in case (3) using a primer specific for the centromeres of acrocentric chromosomes (first experiment) or a primer specific for the centromeres of a subset of meta- and submetacentric chromosomes including chromosome 6 (second experiment). It allowed us to demonstrate that the breakpoints occurred in the centromeric region of chromosome 16 and in the p. arm of chromosome 6, just above the centromere.

Does the 1/29 Robertsonian translocation affect the fertility of Blonde d'Aquitaine breed bulls?

The effects of the 1/29 translocation upon male fertility were studied by analysis of the results of 1,350,385 first artificial inseminations with the semen of Blonde d'Aquitaine or Coopelso-93 bulls (n=220). A binomial logit model was designed, taking into account the translocation of sire, breed of sire, breed of dam, year, AI center, and all interactions between translocation, and breed of sire, and breed of dam. Male fertility was not affected by the 1/29 translocation, and the nonreturn rates at 60 to 90 days of Blonde d'Aquitaine females inseminated with the semen of carrier bulls (135,632 first AI) or noncarrier bulls (585,949 first AI) were 74.88% and 74.75%, respectively.

A new case of Robertsonian translocation in cattle.

A new Robertsonian translocation was found in several animals of the Blonde d'Aquitaine breed. The fused chromosome analyzed by G- and R-banding results from the fusion of chromosomes 21 and 27. C-banding suggests that the fused chromosome is dicentric.

Male-to-male transmission of the hypertelorism-hypospadias (BBB) syndrome.

A boy and his father with the hypertelorism-hypospadias (BBB) syndrome are described. This example of male-to-male transmission is evidence that the BBB syndrome is not due to an X-linked gene.

[Diffuse superficial nephroblastomatosis. Chemotherapy. 1 case]. / Néphroblastomatose diffuse superficielle. Traitement par chimiothérapie. 1 observation.

A case of superficial diffuse nephroblastomatosis involving both kidneys in a 14-months old child is reported. Urographic and arteriographic results as well as the still little-known ultrasonographic images made it possible to determine pre-operatively the nature of the tumour and to exclude the initial diagnosis of Wilm's tumour. A relatively non-aggressive chemotherapy resulted in complete involution of the subcapsular tumoral envelope. The close embryogenic and oncogenic relationship between nephroblastoma and nephroblastomatosis is recalled.

[Chromosomal structure or porcine lymphocytes effected by food additives]. / Structure chromosomique des lymphocytes du porc et additifs alimentaires.

Different concentrations of food additives were introduced in cultures of pig lymphocytes. No special chromosomal damage were induced by anticoccidians. On the contrary some antibiotics caused chromosomic anomalies. Chloramphenicol and furazolidone assayed in vitro and in vivo had also an antimitotic effect. The purpose of this work was to know the cytotoxic effect of some substances: a preliminary and cheap test could be a cytogenetic examination in vitro.

[Induced hyperglycemia and its relationship to underweight fetuses: study on a newborn infant]. / L'hyperglucosémie provoquée et ses relations avec l'hypotrophie foetale: étude chez le nouveau-né

A study was carried out on hyperglycaemia induced by intravenous administration of glucose between the 1st and 4th day of life in healthy new-born infants and in underweight newborns. The blood glucose level in underweight infants is slightly lower than that in healthy new-born infants. The level of insulin in the blood is much lower in the underweight child after 30 minutes. Although the levels of insulin and Glucagon in the blood vary between the two groups the ratio of Glucagon to insulin is constant and evolves constantly. The ratio is higher the more underweight the child is. It is possible that this can help to maintain the level of blood glucose sufficiently high in the underweight new-born infant.