ABSTRACT
Las alteraciones cromosómicas son una importante causa de muerte en humanos. Sudiagnóstico cuenta con nuevas herramientas que están cada vez más al alcance y permitencorrelacionar los hallazgos de los estudios fetales y placentarios; sin embargo, no entodas las instituciones de salud colombianas se cuenta con tales recursos. Se reportaun caso de trisomía 13, corroborada por hibridación fluorescente in situ (FISH) y seanalizan las manifestaciones histológicas encontradas en la placenta, la cual sí puedeser estudiada de manera rutinaria...
Chromosome alterations are a major cause of death in humans; diagnosis is now aided bynew technology which allows for cross checking on fetal and placental studies. Althoughmany Colombian medical institutions have inadequate access to this technology, weare able to report on a case of Trisomy 13 in which diagnosis was carried out withFluorescence in situ hybridization (FISH) and the histologic manifestations of theplacenta were analyzed following routine procedures...
Subject(s)
Placenta/anatomy & histology , Trisomy/diagnosis , Chromosome Structures/classificationABSTRACT
The two accessions of B. dura analyzed (DU01 and DU02) are hexaploid (2n = 6x = 54), derived from x = 9. Meiotic abnormalities, such as precocious chromosome migration to the poles, laggards and micronuclei, were recorded in low frequency in both accessions. The few multivalent chromosome association at diakinesis and meiotic stability suggested that hexaploidy probably resulted from chromosome doubling. In DU02, chromosome transfer (cytomixis) among meiocytes, involving part or the entire genome was observed. The implication of these findings for the Brachiaria breeding is discussed.
Os dois acessos de B. dura analisados (DU01 e DU02) são hexaplóides (2n = 6x = 54), derivados de x = 9. Anormalidades meióticas como migração precoce de cromossomos para os polos, cromossomos retardatários e micronúcleos foram observados em baixa frequência em ambos os acessos. A presença de poucas associações cromossômicas em diacinese e a estabilidade meiótica sugere que a hexaploidia provavelmente resultou de duplicação cromossômica. No acesso DU02 observou-se transferência de cromossomos (citomixia) entre meiócitos, envolvendo parte ou todo o genoma. As implicações destes resultados para o melhoramento de Brachiaria são discutidas.