Characterization of the porcine CDKN3 gene as a potential candidate for congenital splay leg in piglets

We have isolated ESTs differentially displayed in skeletal muscle of healthy neonatal piglets and piglets suffering from congenital splay leg, respectively. One fragment was identified as the porcine homologue of cyclin-dependent kinase inhibitor 3 (CDKN3) and mapped to SSC1q23-27 by analysis of somatic pig-rodent cell hybrids. The gene plays a key role in cell cycling and mutations of CDKN3 and its overexpression are related to carcinogenesis in human (Yeh et al. 2000, Lee et al. 2000). Sequencing of the porcine gene revealed a genomic structure similar to human CDKN3 consisting of eight exons. Due to different intron lengths the porcine gene spans only 13 kb of genomic sequence compared to 23.3 kb in human. The coding region of the porcine gene contains 12 SNPs based on sequences of 4 splay leg and 3 control individuals. The SNPs result in the alteration of six different amino acids in the deduced amino acid sequence. However, there was no relationship between polymorphisms and splay leg syndrome. Porcine CDKN3 is expressed in all investigated tissues (skeletal muscle, heart, liver, duodenum and spleen). Beside full length transcripts we found a variety of aberrantly transcribed cDNA in clones derived from M. biceps femoris of healthy as well as of splay leg piglets. The aberrations include deletions of 1 - 3 exons as well as partial deletions in single exons. All alternative transcripts coexist with normal cDNA. These findings are similar to results in human where 21 aberrant transcripts were described in cancerous and healthy hepatic tissue, respectively (Yeh et al. 2000). Additionally, we observed transcripts with insertions of intronic sequences. The observed high transcriptional variability of the gene and its function in controlling cell cycle progression may indicate an involvement in porcine splay leg syndrome, which is assumed to be a compensatory hypoplasia of skeletal muscle. Comparative studies of the expression of pCDKN3 in healthy and affected piglets will further elucidate the role of this gene. (Texte intégral)

Bibliographic Details

Main Authors:	Maak, S., Jaesert, S., Neumann, K., Von Lengerken, G.
Format:	conference_item biblioteca
Language:	eng
Published:	CIRAD
Subjects:	L10 - Génétique et amélioration des animaux, porcelet, résistance génétique, http://aims.fao.org/aos/agrovoc/c_5872, http://aims.fao.org/aos/agrovoc/c_35130,
Online Access:	http://agritrop.cirad.fr/512104/
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