Fertility of male and female mice heterozygous for the reciprocal translocation T(7;17)3BKM.

The present paper describes the fertility of male and female mice heterozygous for the reciprocal translocation T(7;17)3BKM. This translocation was induced by gamma rays in the spermatozoa of an irradiated parent. It is characterized by "asymmetrical" localization of the breakpoints, distally in Chromosome 7 (7F5) and proximally in Chromosome 17 (17B1). The data presented here relate only those matings in which, for both partners, heterozygosity or normality could be confirmed cytogenetically. The results indicate that both male and female translocation heterozygotes are fertile, their mean litter size being reduced to about 50% of that of normal littermates. This leads to the conclusion that the multivalents mainly undergo either alternate or adjacent-1 2:2 segregation. No viable tertiary trisomics were observed among the progeny of the translocation carriers. Analysis of the frequency of the different types of multivalents in diakinesis-metaphase I spermatocytes showed a significant predominance of chain-type figures (CIV and CIII+I), with chains of four elements (CIV) being more frequent than other configurations. This demonstrates that the small marker chromosome remains attached by one of its segments to the tetravalent.     

Three Novel <Emphasis Type="Italic">NF1</Emphasis> Gene Mutations in a Cohort of Bulgarian Neurofibromatoses Patients

Neurofibromatosis (NF) is a clinically heterogeneous autosomal dominant disorder. Three distinct forms have been identified: neurofibromatosis type 1 (NF1), type 2 (NF2) and schwannomatosis. In the present study, we report clinical and genetic findings in the NF1 and NF2 genes in a cohort of 27 Bulgarian patients, with 18 cases (67%) genetically verified. Both NF1 and NF2 genes were screened by Sanger sequencing on DNA samples. The Sanger negative samples were screened by Multiplex Ligation-dependent Probe Amplification (MLPA) for deletions and duplications. The results from genetic testing revealed three novel mutations and fifteen previously reported ones (13 in the NF1 gene and 2 in the NF2 gene). The novel variants in the NF1 gene are a splice site mutation c.4725-1G>A, a small deletion of five bases c.823delATCTT, p.Leu275ValfsTer14, and a single base duplication c.6547dupC, p.Arg2183ProfsTer11. The novel splice site mutation is manifested by multiple “café au lait” macules and neurofibromas. Both novel out of frame mutations were found in patients with multiple “café au lait” spots and focal epilepsy. A segmental neurofibromatosis (SNF1) is restricted to one or more body segments. Here we present a case with SNF1 caused by a somatic deletion of exons 1 to 12 of the NF1 gene which is manifested by multiple neurofibromas in the right hand. Two nonsense mutations are found in the NF2 gene. Our study adds three novel mutations to the NF1 mutation spectra and contributes to the clinical-genetic NF1-characterization. Here we report strikingly different phenotypic spectra caused by the same mutation in a single family. Our findings contribute to the genotype- phenotype correlations which are difficult to establish, due to the extremely complex NF phenotype being a combination of clinical features.     

Interspecific Infanticide and Infant‐Directed Aggression by Spider Monkeys (Ateles hybridus) in a Fragmented Forest in Colombia

Interspecific aggression amongst nonhuman primates is rarely observed and has been mostly related to scenarios of resource competition. Interspecific infanticide is even rarer, and both the ultimate and proximate socio‐ecological factors explaining this behavior are still unclear. We report two cases of interspecific infanticide and five cases of interspecific infant‐directed aggression occurring in a well‐habituated primate community living in a fragmented landscape in Colombia. All cases were initiated by male brown spider monkeys (Ateles hybridus) and were directed toward infants of either red howler monkeys (Alouatta seniculus: n = 6 cases) or white‐fronted capuchins (Cebus albifrons: n = 1 case). One individual, a subadult spider monkey male, was involved in all but one case of interspecific infanticide or aggression. Other adult spider monkeys participated in interspecific aggression that did not escalate into potentially lethal encounters. We suggest that competition for food resources and space in a primate community living in high population densities and restricted to a forest fragment of ca. 65 ha might partly be driving the observed patterns of interspecific aggression. On the other hand, the fact that all but one case of interspecific infanticide and aggression involved the only subadult male spider monkey suggests this behavior might either be pathological or constitute a particular case of redirected aggression. Even if the underlying principles behind interspecific aggression and infanticide are poorly understood, they represent an important factor influencing the demographic trends of the primate community at this study site. Am. J. Primatol. 74:990‐997, 2012. © 2012 Wiley Periodicals, Inc.     

高温强光胁迫对苹果果皮PPO活性的影响

苹果果实日烧是一种普遍发生的生理病害,最常见的特征之一就是在果实表面出现褐变。通常认为PPO与植物的酶促褐变密切相关。研究了自然和控制条件下,高温强光胁迫对果实PPO活性的影响,以便揭示高温强光胁迫下苹果果实褐变与PPO活性之间的联系。结果表明：高温和强光胁迫与果皮PPO活性变化密切相关。就树冠不同方位而言,西南方位是高温和强光胁迫最严重的区域,其外围裸露果实的PPO活性也最强。在一定范围内,随着处理温度和光照强度的升高,果皮PPO活性也逐渐增强。短时间剧烈升温能够引起PPO活性骤然上升。在同样程度的高温胁迫下,提高环境湿度有利于抑制果皮PPO活性,从而减轻褐变症状的发生。室内外试验一致证实：果实日烧褐变现象与高温强光胁迫下果皮组织PPO活性大幅度提高有直接关系。