Detection of a new variant of rabbit haemorrhagic disease virus in wild rabbits in Spain

El virus de la enfermedad hemorrágica del conejo (RHDV) suele causar elevadas mortalidades tanto en conejos domésticos como en silvestres. Hasta el momento actual, todas las variantes víricas detectadas en la Península Ibérica proceden de un único ancestro común estrechamente emparentado con las primeras cepas patógenas aisladas en esta área. Con objeto de estudiar la epidemiología de esta enfermedad, durante los años 2010 y 2011 se monitorizó una población experimental de conejos silvestres con el fin de detectar los cadáveres de conejos muertos por esta enfermedad. La presencia de ARN viral en el tejido hepático de los cadáveres fue determinada mediante RT-PCR, y en el caso de resultar positiva se procedió a su secuenciación. Durante 2010 se diagnosticaron un total de 12 conejos muertos por RHD, mientras que en 2011 se diagnosticó un total de 9 cadáveres. En todos los conejos muertos por RHD en 2010 y en tres de 2011 la cepa identificada fue la original de la población, sin embargo, en cinco de los restantes seis cadáveres se identificó una cepa diferente. Filogenéticamente, esta cepa es relativamente distante de los grupos de lagovirus, tanto patógenos como apatógenos, descritos hasta la actualidad y, por similitud, esta cepa podría asimilarse a la nueva variante descrita en Francia en 2010 implicada en episodios de elevada mortalidad por RHD en granjas cunícolas de aquel país. Nuestro hallazgo coincidió en el tiempo con la ocurrencia de brotes atípicos de RHD en granjas cunícolas españolas durante 2011, similares a los ocurridos en Francia, por lo que los resultados del presente trabajo confirmarían la presencia de esta nueva variante en España y sugerirían su más que probable implicación en los brotes atípicos detectadosRabbit haemorrhagic disease virus (RHDV) is a virulent calicivirus that causes high mortality both in domestic and wild rabbits. It appears to be a mutant form of a benign virus that existed in Europe long before the first outbreak. To date, however, phylogenetic data indicate that all the field strains of RHDV found in the Iberian Peninsula have a common ancestor closely related to pathogenic strains isolated during the first RHD outbreaks in this area. In order to study RHD epidemiology, an experimental wild rabbit population was monitorized twice at week during 2010 and 2011 years in order to find rabbits dead by the disease. Detection of viral RNA in liver tissue of carcasses was conducted by RT-PCR reaction and, when positive, PCR products were purified and sequenced. Across 2010, 12 rabbits were found dead by RHD, whereas nine rabbits were found dead in 2011. The original RHDV field strain was identified in all dead rabbits found in 2010 and in three of 2011. However, a new strain was identified in five of remaining six carcasses found in this year. Phylogenetic analysis showed that this new viral strain would be a member of the new variant of RHDV recently detected in France in 2010. This variant is relatively distant from already described pathogenic and non-pathogenic lagoviruses, and it has been reported to cause increased mortalities in French rabbitries. In Spain, several atypical RHD outbreaks have been described affecting rabbitries during 2011 and this variant has been proposed as the putative aetiological agent. This survey confirms that this new RHDV variant would be already present in Spain

Diagnóstico mediante PCR-duplex de la nueva variante RHDVb del virus de la enfermedad hemorrágica en conejos

Publishe

Y chromosome haplotype characterization of Tunisian sheep breeds

This study aimed to investigate Y chromosomal haplotypes in the main Tunisian sheep breeds. For this purpose, we sequenced 2 regions of SRY (549-bp and 598-bp fragments) and 1 region in each of the AMELY and DBY genes in Barbarin, Western Thin Tail, Sicilo Sarde, and Black Thibar breeds. In addition, we analyzed the diversity at the SRYM18 microsatellite locus and detected 4 alleles of 139, 141, 143, and 145 bp. The sequencing analysis did not reveal any polymorphism in the AMELY or DBY regions; however, 2 samples carried the G allele in the 549-bp fragment of SRY. A total of 5 haplotypes, H4, H5, H6, H8, and H12, were found in the 4 breeds. The most common haplotype was H8 (55.5%), followed by H6 (34.5%), while other haplotypes were observed at low frequencies. H4 and H5 haplotypes were observed only in Western Thin Tail and Black Thibar breeds, respectively. In spite of the small area of Tunisia, a high Y chromosome diversity was observed. The results underlined the genetic relation of Tunisian sheep breeds with Middle Eastern, African, and European sheep breedsPublishe

Assessing the age-related relationship between plasma anti-Müllerian Hormone (AMH) and ovarian follicle population in prepubertal ewes (abstract)

Publishe

Efecto de la suplementación con vitamina E en los ácidos grasos poliinsaturados y en la expresión de genes relacionados con el metabolismo lipídico en L. Thoracis de corderos ligeros

Publishe

Asociación de los genes LEPR y DGAT1 con caracteres reproductivos en ovejas de rasa aragonesa

Estudios de gestión técnico-económicos en explotaciones de Rasa aragonesa han mostrado que algunos de los factores asociados con un incremento de la rentabilidad de las ganaderías son la disminución de periodos improductivos y el incremento del número de corderos vendidos por oveja y año (Pardos et al., 2016; Pardos y Fantova, 2018; Pardos et al., 2022), que están relacionados con la mejora de los índices de prolificidad, edad al primer parto y estacionalidad reproductiva. El objetivo de este trabajo fue llevar a cabo un estudio de asociación con el fin de identificar SNPs asociados con caracteres reproductivos, mediante un panel de 192 SNPs utilizado en Rasa aragonesa para asignación de paternidad y para el genotipado de genes funcionales.Este trabajo ha sido financiado con fondos FEDER, y de los proyectos FITE TERGENOVID, Grupo de Cooperación VAGESO (GCP2019003800) y Grupo SAGAS Ref. A14_20R) del Gobierno de Aragón. K. Lakhssassi está financiada por un contrato del Ministerio de Ciencia, Innovación y Universidad (BES-2017-080154

Determinación de diferencias en el transcriptoma de muestras sanguíneas de machos de raza Rasa Aragonesa con diferente comportamiento sexual

Raza Rasa aragonesaPublishe

Experimental Study of the Mechanical Transmission of Rabbit Hemorrhagic Disease Virus (RHDV2/b) by Aedes albopictus (Diptera: Culicidae) and Phlebotomus papatasi (Diptera: Psychodidae)

Rabbit hemorrhagic disease (RHD) is caused by a lagovirus mainly affecting European rabbits (Oryctolagus cuniculus), although other European and North American lagomorph species are also susceptible to fatal infection by the new viral variant RHDV2/b. In the present work, direct mechanical transmission of the rabbit hemorrhagic disease virus (RHDV2/b variant) by the hematophagous Diptera Aedes albopictus (Skuse) (Diptera: Culicidae) and the sand fly Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) was tested. For each species, six and three laboratory rabbits were exposed to bites of dipterous females partially fed on RHDV2/b viral suspension 2 h and 24 h prior to exposure, respectively. The rabbits were then monitored for clinical changes and mortality for 35 d, and seroconversion was assessed by indirect ELISA. No rabbit died or showed clinical signs of disease, and seroconversion was recorded in two rabbits challenged with P. papatasi females fed the viral suspension 2 h prior to exposure. The number of RHDV2/b RNA copies/female was higher in Ae. albopictus than in P. papatasi but the decrease over time of RNA load in Ae. albopictus was greater than that in P. papatasi. The results of this study suggest the inability of Ae. albopictus to serve as a direct mechanical vector of RHDV2/b, but sand flies could play a role in the local transmission of RHD.Publishe

Exploring the vomeronasal organ transcriptome in Rasa aragonesa rams with different sexual behaviour

Raza Rasa aragonesaPublishe