Monomorphic subtelomeric DNA in the filamentous fungus, Metarhizium anisopliae, contains a RecQ helicase-like gene.

In most filamentous fungi, telomere-associated sequences (TASs) are polymorphic, and the presence of restriction fragment length polymorphisms (RFLPs) may permit the number of chromosome ends to be estimated from the number of telomeric bands obtained by restriction digestion. Here, we describe strains of Metarhizium, Gliocladium and Paecilomyces species in which only one or a few telomeric bands of unequal intensity are detectable by Southern hybridization, indicating that interchromosomal TAS exchange occurs. We also studied an anomalous strain of Metarhizium anisopliae, which produces polymorphic telomeric bands larger than 8 kb upon digestion of genomic DNA with XhoI. In this case, the first XhoI site in from the chromosome end must lie beyond the presumed monomorphic region. Cloned telomeres from this strain comprise 18?26 TTAGGG repeats, followed at the internal end of the telomere tract by five repeats of the telomere-like sequence TAAACGCTGG. An 8.1-kb TAS clone also contains a gene for a RecQ-like helicase, designated TAH1, suggesting that this TAS is analogous to the Y elements in yeast and the subtelomeric helicase ORFs of Ustilago maydis (UTASRecQ) and Magnaporthe grisea (TLH1). The TAS in the anomalous strain of M. anisopliae, however, appears distinct from these in that it is found at most telomeres and its predicted protein product possesses a significantly longer N-terminal region in comparison to the M. grisea and U. maydis helicases. Hybridization analyses showed that TAH1 homologues are present in all other anomalous M. anisopliae strains studied, as well as in some other polymorphic strains, where the recQ-like gene also appears to be telomere-associated.Published online: 2 June 2005

Ofertas de suplementos múltiplos em tourinhos anelorados na fase de recria, em pastagens durante o período da seca: produção e eficiência microbiana.

O uso de suplementos múltiplos para bovinos visa aumentar o aporte de nutrientes, para melhor atender às exigências nutricionais. Neste contexto, avaliou-se a digestibilidade em tourinhos anelorados em fase de recria, recebendo diferentes ofertas de suplementos em pastagem de Brachiaria decumbens. A área foi dividida em cinco piquetes de 2,0 ha cada. Foram utilizados 30 tourinhos, com peso e idade iniciais médios de 230,0 ±6,14 kg e 8,5 ±0,18 meses, em delineamento inteiramente casualizado, contendo cinco tratamentos, sendo quatro ofertas de suplementos, mais mistura mineral (MM) e seis repetições. Foram avaliados a MM (60g/animal) e suplementos múltiplos, formulados para atender diferentes níveis de suplementação diariamente nas quantidades de 0,5, 1,0, 1,5 e 2,0 kg/animal e suprir 300g/dia de PB. O consumo de suplemento aumentou (P<0,10) a produção de proteína microbiana (PMic), quando comparado com os animais do grupo controle. A produção de PMic apresentou comportamento quadrático com ponto de máxima produção de 404,47 gramas na quantidade de 1,34kg de suplemento. A eficiência de síntese microbiana (EFMic) não diferiu entre os animais do grupo controle e os suplementados. Contudo, observa-se um comportamento quadrático com máxima eficiência 160,38 g/kg de NDT para oferta de 1,18 kg de suplemento. Observa-se que o ponto (1,18 kg) onde ocorreu a máxima EFMic foi inferior ao valor (1,34 kg) em que ocorreu a máxima produção de PMic. Conclui-se que, o ponto ótimo entre produção e eficiência de síntese de proteína microbiana, está entre as ofertas de suplemento diárias de 1,18 e 1,34 kg/animal

Energy and protein requirements of young Holstein calves in tropical condition.

Our objective was to estimate the energy and protein requirements of Holstein young calves up to 87 days old. Forty-two Holstein calves aged 4 days were used. From these, ten were randomly selected and slaughtered to compose the baseline slaughter (BS) group. The remaining calves were randomly assigned to eight treatments in a 4 × 2 factorial using a completely randomized design. The treatments were 2, 4, 6, and 8 kg/day of milk (297 g/kg CP; 319 g/kg of fat) fed twice daily, and then harvested at 59 or 87 days of age. Calves were fed a starter (193 g/kg CP; 133 g/kg NDF) ad libitum in all treatments. The calves slaughtered at 87 days of age had milk replaced by Coast-cross (Cynodoon sp.) hay (125 g/kg CP; 728 g/kg NDF). The net requirement of energy for maintenance (NEm) was 0.36 MJ/kg EBWG, with efficiency of utilization of energy for maintenance (km) of 59.4 %. The equation obtained to estimate the net requirement of energy for gain (NEg; MJ/d) was 4.40 × EBW0.099, with the efficiency of utilization of energy for gain (kg) equal to 46.5 %. The observed requirements of net and metabolizable protein for maintenance (NPm and MPm) were 3.67 and 3.88 g/kg BW0.75, respectively. The efficiency of use of metabolizable protein for maintenance (kpm) was 94.6 %. The predicted requirements were higher than those observed in the literature, and this study demonstrated that the requirements of newborn calves are higher than the recommended