Fourty-six non-castrated, halothane-free, male Landrace pigs were genotyped by PCR-RFLP for the Rsa I polymorphism in the PIT1 gene and classified into AA and AB genotypes. Total RNA was extracted from the pituitaries and the relative quantities of growth hormone (GH) mRNA were determined by semi-quantitative RT-PCR. Pigs with the AB genotype had higher levels of GH mRNA than those with the AA genotype (p = 0.034; Kruskal-Wallis test). This result suggests that the Rsa I polymorphism may be involved in Pit-1 protein expression or function, which in turn may influence GH transcription and expression. Thus, the Rsa I PIT1 gene polymorphism in this pig line may be used as a molecular marker to identify higher GH expression and possibly select for carcass and performance traits affected by GH.

One of the commonest neotropical stingless bees is Tetragonisca angustula (Latreille, 1811), popularly known in Portuguese as jataí, which occurs in variable nesting sites from Mexico to Argentina. We used 18 primers to generate 218 RAPD markers which we used to determined the genetic distance between T. angustula populations from 25 localities in three different Latin America countries, using Tetragonisca weyrauchi from the Brazilian state of Acre and the common honey bee (Apis mellifera) as outgroups. Genetic distance, calculated as the Percentage of Dissimilarity (14%), based on all markers divided the T. angustula population into eastern (group 1) and western (group 2) groups. However, we were able to separate the two groups by using only two primers that have generated five specific molecular markers. The eastern group consists of T. angustula angustula which occurs from Panama to the Brazilian states of Maranhão and northern Minas Gerais and has spread through the Brazilian Atlantic Forest as far as the southern Brazilian state of Santa Catarina. Group 2 is made up of T. angustula fiebrigi which has a more southerly and western distribution, occurring only in the western Brazilian states of Mato Grosso and Mato Grosso do Sul as well as the west of some other Brazilian states (Goiás, Minas Gerais, São Paulo, Paraná and Santa Catarina) and northeastern Argentina.