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A new case of a Robertsonian translocation diagnosed in an infertile bitch of West Highland White Terrier breed is reported. Cytogenetic analyses were performed with the use of Giemsa staining, Q-, C- and Ag-I banding techniques and FISH with canine whole X chromosome paint. The karyotype of this bitch was described as 77,XX der (8;14)(q10;q10).

The present study shows new chromosomal localisation of four canine cosmid clones in the Chinese raccoon dog genome by using dual colour FISH. This approach facilitates rapid physical localisation of markers and will improve the determination of their order on chromosomes. The present new assignments increase the number of physically mapped markers in the Chinese raccoon dog to 25.

Rapid development of the canine marker genome map facilitates genome mapping of other Canidae species. In this study we present chromosomal localization of 18 canine-derived cosmid probes containing microsatellites in the arctic fox (Alopex lagopus) and Chinese raccoon dog (Nyctereutes procyonoides procyonoides) genomes by the use of fluorescence in situ hybridization (FISH). The chromosome localizations in the arctic fox are in general agreement with data obtained from comparative genome maps of the dog and the fox. However, our studies showed that the order of the loci on some chromosomes was changed during karyotype evolution. Therefore, we suggest that small intrachromosomal rearrangements took place.

Congenital malformations resulting in late abortions and stillbirths affect the economic wellbeing of producers and the welfare of cattle in breeding programs. An extremely high incidence of stillbirths of “half-sized” calves of normal karyotype and uninflated lungs was diagnosed in the progeny of the Finnish Ayrshire (Bos taurus) bull - YN51. No other visible anatomical abnormalities were apparent in the stillborn calves. We herein describe the positional identification of a 110 kb microdeletion in the maternally imprinted PEG3 domain that results in a loss of paternal MIMT1 expression and causes late term abortion and stillbirth in cattle. Using the BovineSNP50 BeadChip we performed a genome-wide half-sib linkage analysis that identified a 13.3 Mb associated region on BTA18 containing the maternally imprinted PEG3 domain. Within this cluster we found a 110 kb microdeletion that removes a part of the non-protein coding MER1 repeat containing imprinted transcript 1 gene (MIMT1). To confirm the elimination of gene expression in calves inheriting this deletion, we examined the mRNA levels of the three maternally imprinted genes within the PEG3 domain, in brain and cotyledon tissue collected from eight fetuses sired by the proband. None of the fetuses that inherited the microdeletion expressed MIMT1 in either tissue. The mutation, when inherited from the sire, is semi-lethal for his progeny with an observed mortality rate of 85%. The survival of 15% is presumably due to the incomplete silencing of maternally inherited MIMT1 alleles. We designed a PCR-based assay to confirm the existence of the microdeletion in the MIMT1 region that can be used to assist cattle breeders in preventing the stillbirths.

Een tien maanden oude, vermeend vrouwelijke, intacte Franse buldog werd op de Faculteit Diergeneeskunde te Merelbeke (UGent) aangeboden met een vergrote clitoris en purulente vaginale uitvloei. Als therapie werd voorgesteld om de vergrote clitoris te verwijderen om verdere irritatie te vermijden en tegelijkertijd een gonadectomie uit te voeren aangezien de eigenaars geen fokplannen hadden. Intraoperatief werd een afwijkende genitaaltractus vastgesteld, waarbij macroscopisch een normaal uitziende baarmoeder aanwezig was maar waarbij de gonaden testes leken in plaats van ovaria. Histologisch onderzoek van het verwijderde weefsel toonde aan dat het inderdaad over bilaterale testes aansluitend op een normale baarmoeder ging. Karyotypering en de moleculaire analyse van het SRY-gen resulteerden in een 78,XX SRY-negatief karyotype. Bij de Franse buldog werd bijgevolg finaal een 78,XX SRY-negatief testiculaire aandoening van seksuele differentiatie, i.e. “disorder of sex development” (DSD) gediagnosticeerd.

Thirteen candidate genes for human obesity were selected for cytogenetic mapping by FISH in the pig genome. Among them, 6 genes were assigned to chromosomes for the first time (NR3C1, GNB3, ADRB1, ADRB2, ADRB3 and UCP1). Location of the other 7 genes (INSIG2, LIPIN1, PLIN, NAMPT, ADIPOQ, UCP2 and UCP3), earlier mapped by somatic cell hybridization or with the use of a radiation hybrid panel, was verified (INSIG2) or more precisely described. The genes were assigned to the following chromosomes: INSIG2 to SSC15q12, LIPIN1 to SSC3q26, NR3C1 to SSC2q29, PLIN to SSC7q15, GNB3 to SSC5q21, NAMPT to SSC9q23, ADIPOQ to SSC13q41, ADRB1 to SSC14q28, ADRB2 to SSC2q29, ADRB3 to SSC15q13-14, UCP1 to SSC8q21-22, and both UCP2 and UCP3 to SSC9p24. Most of the genes were located within known QTL for pig fatness traits.

Background SRY-positive XX testicular disorder of sex development (DSD) caused by X;Y translocations was not yet reported in domestic animals. In humans it is rarely diagnosed and a majority of clinical features resemble those which are typical for Klinefelter syndrome (KS). Here we describe the first case of SRY-positive XX DSD in a tortoiseshell cat with a rudimentary penis and a lack of scrotum. Results Molecular analysis showed the presence of two Y-linked genes (SRY and ZFY) and a normal sequence of the SRY gene. Application of classical cytogenetic techniques revealed two X chromosomes (38,XX), but further FISH studies with the use of the whole X chromosome painting probe and BAC probes specific to the Yp chromosome facilitated identification of Xp;Yp translocation. The SRY gene was localised at a distal position of Xp. The karyotype of the studied case was described as: 38,XX.ish der(X)t(X;Y)(p22;p12)(SRY+). Moreover, the X inactivation status assessed by a sequential R-banding and FISH with the SRY-specific probe showed a random inactivation of the derivative XSRY chromosome. Conclusions Our study showed that among DSD tortoiseshell cats, apart from XXY trisomy and XX/XY chimerism, also SRY-positive XX cases may occur. It is hypothesized that the extremely rare occurrence of this abnormality in domestic animals, when compared with humans, may be associated with a different organisation of the Yp arm in these species.