RESUMO
A 4-year-old Colombian Creole mare was presented for diagnosis because the external orifice of her cervix was not detectable when a uterine lavage as therapy for uterine fluid accumulation was attempted. Clinical and ultrasonographic evaluation of the genital tract revealed that ovaries were of normal size and showed structures suggestive of regular ovarian activity. However, granular free-floating fluid material distending the uterus was detected by ultrasound. Upon vaginal examination, the normal external cervical morphology was not evident. The vagina ended in a blind bag with a small papilla with no evident external cervical os. Cytology of uterine fluid obtained by transvaginal aspiration showed findings compatible with mucometra. Cytogenetic analysis revealed an abnormal karyotype (63,X and 64,XX both 45% and 65,XXX 10%). A diagnosis of congenital segmental cervical aplasia was proposed possibly related to the mosaicism detected. To our knowledge, this is the first case of this reproductive pathology in a mare with regular ovarian activity and confirmed aneuploidy in mosaic form of the X sex chromosome.
Assuntos
Doenças dos Cavalos , Útero , Aneuploidia , Animais , Colômbia , Feminino , Cavalos , Mosaicismo , Cromossomo XRESUMO
El presente trabajo evidencia desde el punto de vista citogenético la introgresión genética, de origen paterno, de Bos indicus en ganado criollo colombiano descendiente de Bos taurus. Para este estudio se realizó el análisis cariológico de la morfología del cromosoma Y a partir de muestras de sangre heparinizada de 67 bovinos machos pertenecientes a siete razas criollas colombianas. Se reporta la presencia de cuatro ejemplares pertenecientes a la raza Romosinuano (40%) y 10 toros de la raza Casanareña (100%) con cromosoma Y de tipo acrocéntrico característico de Bos indicus, lo cual estaría evidenciando un alto grado de introgresión genética, en estas dos razas, posiblemente originada por la intensiva introducción de sementales de la raza Cebú en la ganadería criolla colombiana. En las otras cinco razas (Blanco Orejinegro (BON), Chino santandereano, Costeño con cuernos, Hartón del valle y Sanmartinero), los toros presentaron el cromosoma Y submetacéntrico, característico de Bos taurus.
This work evidenced, using a cytogenetics approach, that Bos indicus exerted a genetic introgression of paternal origin on Creole Colombian cattle descendent from Bos taurus. Analysis of chromosome Y morphology was carried out in heparinized blood samples of 67 bulls belonging to seven Colombian breeds. We report 4 sires belonging to the Romosinuano breed (40%) and 10 bulls of the Casanareño breed (100%) with acrocentric Y chromosome which is characteristic of Bos taurus. This finding indicates a high degree of genetic introgression in these two breeds probably caused by the continuous input of zebu stallions in the Colombian Creole breeds. In other five Creole breeds (Blanco Orejinegro -BON-, Chino Santandereano, Costeño con Cuernos, Hartón del Valle and Sanmartinero), the bulls had a submetacentric Y chromosome characteristic of Bos taurus.
