A young cow of the Marchigiana breed (central Italy) with normal body conformation and external genitalia underwent routine cytogenetic analyses prior to its use for reproduction. After normal chromosome staining, only one X chromosome was observed with a normal diploid number (2n = 60) in all 200 studied cells. Subsequent cytogenetic analyses by using both CBA- and RBA-banding techniques evidenced that almost all the p arms of the other X chromosome was lacking. Detailed FISH-mapping analyses with BAC covering this Xp arm region demonstrated that this large chromosome region was deleted. RBA-banding showed that the deleted X was late replicating. CGH array analysis evidenced that deletion involves the Xp arm from the telomere to around 39.5 Mb, referring to the BosTau6 cattle genome assembly. This abnormality deletes about 40 Mb of the X chromosome sequence, but, despite the large number of genes deleted, none of them are programmed to escape from inactivation. This can explain the normal phenotype of the female which is actually pregnant. Finally, we evidenced, by analysis of an SNP mapped to the deleted region (SNP rs29024121), that the only normal (e.g. nondeleted) X chromosome present derives from the father. Hence, the deletion has a maternal origin.

Molecular characterization of Xp chromosome deletion in a fertile cow / L. De Lorenzi, E. Rossi, V. Genualdo, S. Gimelli, E. Lasagna, A. Perucatti, A. Iannuzzi, P. Parma. - In: SEXUAL DEVELOPMENT. - ISSN 1661-5425. - 6:6(2012), pp. 298-392. [10.1159/000342189]

Molecular characterization of Xp chromosome deletion in a fertile cow

L. De Lorenzi;P. Parma
2012

Abstract

A young cow of the Marchigiana breed (central Italy) with normal body conformation and external genitalia underwent routine cytogenetic analyses prior to its use for reproduction. After normal chromosome staining, only one X chromosome was observed with a normal diploid number (2n = 60) in all 200 studied cells. Subsequent cytogenetic analyses by using both CBA- and RBA-banding techniques evidenced that almost all the p arms of the other X chromosome was lacking. Detailed FISH-mapping analyses with BAC covering this Xp arm region demonstrated that this large chromosome region was deleted. RBA-banding showed that the deleted X was late replicating. CGH array analysis evidenced that deletion involves the Xp arm from the telomere to around 39.5 Mb, referring to the BosTau6 cattle genome assembly. This abnormality deletes about 40 Mb of the X chromosome sequence, but, despite the large number of genes deleted, none of them are programmed to escape from inactivation. This can explain the normal phenotype of the female which is actually pregnant. Finally, we evidenced, by analysis of an SNP mapped to the deleted region (SNP rs29024121), that the only normal (e.g. nondeleted) X chromosome present derives from the father. Hence, the deletion has a maternal origin.
Cattle ; CGH array ; Deletion Xp ; FISH
Settore AGR/17 - Zootecnica Generale e Miglioramento Genetico
SEXUAL DEVELOPMENT
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/207077
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 7
  • ???jsp.display-item.citation.isi??? 6
social impact