Robertsonian Translocation in a Sex Reversal Dog (XX, SRY negative) May Indicate that the Causative Mutation for This Intersexuality Syndrome Resides on Canine Chromosome 23 (CFA23)

2011 ◽  
Vol 5 (3) ◽  
pp. 141-146 ◽  
Author(s):  
M. Switonski ◽  
I. Szczerbal ◽  
W. Nizanski ◽  
B. Kociucka ◽  
M. Bartz ◽  
...  
2011 ◽  
Vol 56 (No. 5) ◽  
pp. 243-247 ◽  
Author(s):  
J. Dostal ◽  
A. Hrdlicova ◽  
P. Horak

Progressive rod-cone degeneration (PRCD) is a late onset autosomal photoreceptor degeneration found in canines. PRCD in canines is homologous to one form of retinitis pigmentosa (RP) found in humans and displays phenotypic similarity as well as having the identical causative mutation. The PRCD gene was mapped to the centromeric region of canine chromosome 9 (CFA9). We report here a population study of 699 dogs of the following breeds and the following frequencies of the disease-causing mutation: American Cocker Spaniel (0.09), English Cocker Spaniel (0.34), English Springer Spaniel (0.00), Welsh Springer Spaniel (0.00), Flat Coated Retriever (0.00), Golden Retriever (0.00), Chesapeake Bay Retriever (0.14), Nova Scotia Duck Tolling Retriever (0.44), Labrador Retriever (0.07), Poodle Toy (0.45), Poodle Miniature (0.20), Poodle Medium (0.05), Poodle Standard (0.00), Portuguese Water Dog (0.33), Chinese Crested Dog (0.02), Shipperke (0.06), and Australian Cattle Dog (0.00). The disease results in complete blindness in the affected individual in almost every case. The time of onset and disease progression varies between dog breeds as well as between individuals. A modifier gene is likely to segregate in genomic proximity to the PRCD gene and may influence phenotypic expression.


1992 ◽  
Vol 67 (01) ◽  
pp. 063-065 ◽  
Author(s):  
Sherryl A M Taylor ◽  
Jacalyn Duffin ◽  
Cherie Cameron ◽  
Jerome Teitel ◽  
Bernadette Garvey ◽  
...  

SummaryChristmas disease was first reported as a distinct clinical entity in two manuscripts published in 1952 (1, 2). The eponym associated with this disorder, is the surname of the first patient examined in detail and reported by Biggs and colleagues in a paper describing the clinical and laboratory features of seven affected individuals (3). This patient has severe factor IX coagulant deficiency (less than 0.01 units/ml) and no detectable circulating factor IX antigen (less than 0.01 units/ml). Coding sequence and splice junctions of the factor IX gene from this patient have been amplified in vitro through the polymerase chain reaction (PCR). One nucleotide substitution was identified at nucleotide 30,070 where a guanine was replaced by a cytosine. This mutation alters the amino acid encoded at position 206 in the factor IX protein from cysteine to serine. The non conservative nature of this substitution, the absence of this change in more than 200 previously sequenced factor IX genes and the fact that the remainder of the coding region of this gene was normal, all provide strong circumstantial evidence in favour of this change being the causative mutation in this patient. The molecular characterization of this novel mutation in the index case of Christmas disease, contributes to the rapidly expanding body of knowledge pertaining to Christmas disease pathogenesis.


Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1219-1224
Author(s):  
Lara A Underkoffler ◽  
Laura E Mitchell ◽  
A Russell Localio ◽  
Shannon M Marchegiani ◽  
Justin Morabito ◽  
...  

Abstract A Robertsonian translocation results in a metacentric chromosome produced by the fusion of two acrocentric chromosomes. Rb heterozygous mice frequently generate aneuploid gametes and embryos, providing a good model for studying meiotic nondisjunction. We intercrossed mice heterozygous for a (7.18) Robertsonian translocation and performed molecular genotyping of 1812 embryos from 364 litters with known parental origin, strain, and age. Nondisjunction events were scored and factors influencing the frequency of nondisjunction involving chromosomes 7 and 18 were examined. We concluded the following: The frequency of nondisjunction among 1784 embryos (3568 meioses) was 15.9%.Nondisjunction events were distributed nonrandomly among progeny. This was inferred from the distribution of the frequency of trisomics and uniparental disomics (UPDs) among all litters.There was no evidence to show an effect of maternal or paternal age on the frequency of nondisjunction.Strain background did not play an appreciable role in nondisjunction frequency.The frequency of nondisjunction for chromosome 18 was significantly higher than that for chromosome 7 in males.The frequency of nondisjunction for chromosome 7 was significantly higher in females than in males. These results show that molecular genotyping provides a valuable tool for understanding factors influencing meiotic nondisjunction in mammals.


Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Rafael Kretschmer ◽  
Ricardo José Gunski ◽  
Analía del Valle Garnero ◽  
Thales Renato Ochotorena de Freitas ◽  
Gustavo Akira Toma ◽  
...  

Although cytogenetics studies in cuckoos (Aves, Cuculiformes) have demonstrated an interesting karyotype variation, such as variations in the chromosome morphology and diploid number, their chromosome organization and evolution, and relation with other birds are poorly understood. Hence, we combined conventional and molecular cytogenetic approaches to investigate chromosome homologies between chicken and the smooth-billed ani (Crotophaga ani). Our results demonstrate extensive chromosome reorganization in C. ani, with interchromosomal rearrangements involving macro and microchromosomes. Intrachromosomal rearrangements were observed in some macrochromosomes, including the Z chromosome. The most evolutionary notable finding was a Robertsonian translocation between the microchromosome 17 and the Z chromosome, a rare event in birds. Additionally, the simple short repeats (SSRs) tested here were preferentially accumulated in the microchromosomes and in the Z and W chromosomes, showing no relationship with the constitutive heterochromatin regions, except in the W chromosome. Taken together, our results suggest that the avian sex chromosome is more complex than previously postulated and revealed the role of microchromosomes in the avian sex chromosome evolution, especially cuckoos.


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