Transcription variants of SLA-7, a swine non classical MHC class I gene

In pig, very little information is available on the non classical class I (Ib) genes of the Major Histocompatibility Complex (MHC) i.e. SLA-6, -7 and -8. Our aim was to focus on the transcription pattern of the SLA-7 gene. RT-PCR experiments were carried out with SLA-7 specific primers targeting either the full coding sequence (CDS) from exon 1 to the 3 prime untranslated region (3UTR) or a partial CDS from exon 4 to the 3UTR. We show that the SLA-7 gene expresses a full length transcript not yet identified that refines annotation of the gene with eight exons instead of seven as initially described from the existing RefSeq RNA. These two RNAs encode molecules that differ in cytoplasmic tail length. In this study, another SLA-7 transcript variant was characterized, which encodes a protein with a shorter alpha 3 domain, as a consequence of a splicing site within exon 4. Surprisingly, a cryptic non canonical GA-AG splicing site is used to generate this transcript variant. An additional SLA-7 variant was also identified in the 3UTR with a splicing site occurring 31 nucleotides downstream to the stop codon. In conclusion, the pig SLA-7 MHC class Ib gene presents a complex transcription pattern with two transcripts encoding various molecules and transcripts that do not alter the CDS and may be subject to post-transcriptional regulation

The MeLiM Minipig: An Original Spontaneous Model to Explore Cutaneous Melanoma Genetic Basis

Melanoma is the deadliest skin cancer and is a major public health concern with a growing incidence worldwide. As for other complex diseases, animal models are needed in order to better understand the mechanisms leading to pathology, identify potential biomarkers to be used in the clinics, and eventually molecular targets for therapeutic solutions. Cutaneous melanoma, arising from skin melanocytes, is mainly caused by environmental factors such as UV radiation; however a significant genetic component participates in the etiology of the disease. The pig is a recognized model for spontaneous development of melanoma with features similar to the human ones, followed by a complete regression and a vitiligo-like depigmentation. Three different pig models (MeLiM, Sinclair, and MMS-Troll) have been maintained through the last decades, and different genetic studies have evidenced a complex inheritance of the disease. As in humans, pigmentation seems to play a prominent role, notably through MC1R and MITF signaling. Conversely, cell cycle genes as CDKN2A and CDK4 have been excluded as predisposing for melanoma in MeLiM. So far, only sparse studies have focused on somatic changes occurring during oncogenesis, and have revealed major cytological changes and a potential dysfunction of the telomere maintenance system. Finally, the spontaneous tumor progression and regression occurring in these models could shed light on the interplay between endogenous retroviruses, melanomagenesis, and adaptive immune response

Transcriptome hépatique et régulation génétique de la lipogenèse chez le poulet de chair

L'objectif de ce travail est d'identifier des gènes responsables de la variabilité génétique de l'état d'engraissement chez le poulet et les structures génétiques particulières impliqués. Une démarche " gènes candidats " sur deux populations de poulets d'élevage présentant des aptitudes différentes à l'engraissement (grasse ou maigre) a mis en évidence une différence de taux d'ARN messagers (ARNm) pour plusieurs gènes impliqués dans le métabolisme hépatique des lipides (Daval et al., 2000). Une analyse de liaison génétique au caractère adiposité montre que ceux-ci ne sont pas à l'origine de la différence phénotypique observée. Ces résultats suggèrent cependant une régulation coordonnée des gènes de la lipogénése. Suite à cette approche " gènes candidats ", une démarche anonyme par analyse différentielle des ARNm hépatiques, a été mise en place en 1998. Cette approche en differential display (DD) a permis d'isoler plusieurs centaines de fragments d'ADNc potientiellement différentiels entre animaux gras et maigres (Carre et al. 2001) qui ont fait l'objet des travaux présentés dans ce manuscrit. L'étude de l'expression de quelques produits du DD par Northern-blot a permis de montrer que l'un deux, correspond au gène codant le CYP2C45 est 3 fois plus exprimé chez les animaux maigres (Carre et al. 2002). Ces molécules étant connues dans d'autres espèces pour leur capacité à transformer les acides gras polyinsaturés notamment, nous avons cherché à mieux comprendre le fonctionnement du CYP2C45 ex vivo, dans un système cellulaire d'hépatome de poulet (cellules LMH)RENNES-Agrocampus-CRD (352382323) / SudocSudocFranceF

Genome exploration in a melanoma model

Genome exploration in a melanoma model. Séminaire de l'Institut de Radiobiologie Cellulaire et Moléculair

The MeLiM Minipig: an Original spontaneous model to Explore cutaneous melanoma genetic basis

Melanoma is the deadliest skin cancer and is a major public health concern with a growing incidence worldwide. As for other complex diseases, animal models are needed in order to better understand the mechanisms leading to pathology, identify potential biomarkers to be used in the clinics, and eventually molecular targets for therapeutic solutions. Cutaneous melanoma, arising from skin melanocytes, is mainly caused by environmental factors such as UV radiation; however a significant genetic component participates in the etiology of the disease. The pig is a recognized model for spontaneous development of melanoma with features similar to the human ones, followed by a complete regression and a vitiligo-like depigmentation. Three differentpig models (MeLiM, Sinclair, and MMS-Troll) have been maintained through the last decades, and different genetic studies have evidenced a complex inheritance of the disease. As in humans, pigmentation seems to play a prominent role, notably through MC1R and MITF signaling. Conversely, cell cycle genes as CDKN2A and CDK4 have been excluded as predisposing for melanoma in MeLiM. So far, only sparse studies have focused on somatic changes occurring during oncogenesis, and have revealed major cytological changes and a potential dysfunction of the telomere maintenance system. Finally, the spontaneous tumor progression and regression occurring in these models could shed light on the interplay between endogenous retroviruses, melanomagenesis, and adaptive immune response

The MeLiM pig : a model for cutaneous melanoma

The MeLiM pig : a model for cutaneous melanoma. COST Action BM1308 “Sharing Advances in Large Animal Models” (SALAAM

Differential expression and genetic variation of hepatic messenger RNAs from genetically lean and fat chickens

International audienc

Differential expression and genetic variation of hepatic messenger RNAs from genetically lean and fat chickens

International audienc

Characterization of differential genes from lean and fat chickens

*INRA UMR Génétique Animale 35042 Rennes (FRA) Diffusion du document : INRA UMR Génétique Animale 35042 Rennes (FRA)National audienc