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Results of rearing and breeding chimpanzees at the Primate Center TNO are presented. The colony was built up from 1964 to 1971 by the acquisition of mostly young chimpanzees; thereafter, it was increased by local breeding. The ages at which the animals became reproductive were between 6 and 11 years for the males and between 7 and 15 years for the females. Seventy-six percent of the pregnancies (N = 132) were carried to full term and 87% of these were live births. Fifty-five percent of the babies were nursed by their mothers for 2–10 months. The next pregnancy after an abortion occurred on the average after 7 months; after a carriage to term, this occurred after 11.9 months. The difference was not influenced by the duration of the weaning period. Animals of 2 years or more that had been weaned within a month were more likely to show body rocking than animals weaned later. Cases of disturbed social or reproductive behavior were rare; the first locally bred animals have become reproductively active. Copyright © 1983 Wiley-Liss, Inc., A Wiley Company

Fattening pigs are often infected with campylobacter. To eliminate campylobacter from the pig population, a top-down approach, involving the breeding and reproduction farms, seems appropriate. In order to investigate the effectiveness of a top-down approach, sows' faeces from the following farms were analysed for the presence of campylobacter: one specific pathogen free (SPF) farm, three top-breeding farms with no connection with SPF breeding, and a breeding farm repopulated with SPF sows after a period of vacancy (farm 5). The faeces samples from the SPF farm were free from campylobacter. The three top-breeding farms provided faeces samples which were 98% positive for campylobacter. However, only 22% of the faeces samples from farm 5 were positive for campylobacter. In a period of 20 months, the percentage of sows infected with campylobacter on farm 5 did not significantly increase. Genetic typing with ERIC-PCR and RFLP of campylobacter isolates from one of the top-breeding farms and from farm 5 showed a high diversity of campylobacter types. The results suggest that a campylobacter-free pig population can be established in breeding farms by combining a top-down approach (campylobacter-free top-breeding farms) with a strict regime of hygiene management.

Embryogenesis in plants is a unique process in the sense that it can be initiated from a wide range of cells other than the zygote. Upon stress, microspores or young pollen grains can be switched from their normal pollen development towards an embryogenic pathway, a process called androgenesis. Androgenesis represents an important tool for research in plant genetics and breeding, since androgenic embryos can germinate into completely homozygous, double haploid plants. From a developmental point of view, androgenesis is a rewarding system for understanding the process of embryo formation from single, haploid microspores. Androgenic development can be divided into three main characteristic phases: acquisition of embryogenic potential, initiation of cell divisions, and pattern formation. The aim of this review is to provide an overview of the main cellular and molecular events that characterize these three commitment phases. Molecular approaches such as differential screening and cDNA array have been successfully employed in the characterization of the spatiotemporal changes in gene expression during androgenesis. These results suggest that the activation of key regulators of embryogenesis, such as the BABY BOOM transcription factor, is preceded by the stress-induced reprogramming of cellular metabolism. Reprogramming of cellular metabolism includes the repression of gene expression related to starch biosynthesis and the induction of proteolytic genes (e.g. components of the 26S proteasome, metalloprotease, cysteine, and aspartic proteases) and stress-related proteins (e.g. GST, HSP, BI-1, ADH). The combination of cell tracking systems with biochemical markers has allowed the key switches in the developmental pathway of microspores to be determined, as well as programmed cell death to be identified as a feature of successful androgenic embryo development. The mechanisms of androgenesis induction and embryo formation are discussed, in relation to other biological systems, in special zygotic and somatic embryogenesis. © The Author [2005]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved. Chemicals / CAS: Plant Growth Regulators

Rats and mice are the most commonly used species as laboratory animal models of diseases in biomedical research. Environmental factors such as cage size, number of cage mates and cage structure such as environmental enrichment can affect the physiology and behavioural development of laboratory animals and their well-being throughout their lives. Therefore compromising the animals' well-being due to inadequate environmental conditions would diminish the value of the research models. In order to improve laboratory animals' well-being and promote the quality of animal based biomedical research, it is fundamentally important that the environment of the animals meets the animals' species typical behavioural needs. Standardisation of environmental enrichment for laboratory rats and mice therefore should provide possibilities for the animals to engage in at least the essential behavioural needs such as social contact, nest building, exploring and foraging. There is a wide variety of environmental enrichment items commercially available for laboratory mice and rats. However, how these items are used by the animals, their practicality in the laboratory and whether these enrichments might lead to increased variation in experimental results have not been widely assessed. In this study, we implemented two standardised enrichment items (shelters, nesting materials) for rats and mice at different animal units. We instructed the animal care staff in monitoring the use of enrichment items by the animals by means of a daily score sheet system. The animal staff's viewpoint on practicality of the standardised enrichment program was assessed with a monthly score sheet survey. Also we assessed whether the enriched environment affected breeding results and contributed to an increase in variation of experimental data from several participating current studies. Our results show that the animals readily used the provided enrichment items. A slight increase in workload for the animal staff was reported. However, the overall judgement was mainly reported as good. Breeding results and variation in experimental data did not reveal differences as compared to data from previous housing and/or non enriched housing conditions. Overall, the results indicate that standard environmental enrichment that is species appropriate may enhance the animal's well-being without undesirable side effects on the experimental outcome and daily working routine of the animal care staff.

Objective-Cholesterol 7α-hydroxylase (cyp7a1) catalyzes the rate-limiting step in conversion of cholesterol to bile acids. To study the relationship between bile acid biosynthesis and triglyceride metabolism, we cross-bred mice lacking cyp7a1 on a hyperlipidemic APOE*3-Leiden background. Methods and Results-Female mice received a chow or lipogenic diet. On both diets, fecal bile acid excretion was 70% decreased concomitantly with a 2-fold increased neutral sterol output. The differences in bile acid biosynthesis did not change plasma cholesterol levels. However, plasma triglyceride levels decreased by 41% and 38% in the cyp7a1-/- APOE*3-Leiden mice as compared with APOE*3-Leiden mice on chow and lipogenic diet, respectively. Mechanistic studies showed that very-low-density lipoprotein (VLDL)-apolipoprotein B and VLDL-triglyceride production rates were reduced in cyp7a1-/-.APOE*3-Leiden mice as compared with APOE*3-Leiden mice (-34% and -35%, respectively). Cyp7a1 deficiency also increased the hepatic cholesteryl ester and triglyceride content (2.8-fold and 2.5-fold, respectively). In addition, hepatic anti-oxidative vitamin content, which can influence VLDL-production, was lower. Hepatic mRNA analysis showed decreased expression of genes involved in lipogenesis including srebf1. Conclusions-Cyp7a1 deficiency in APOE*3-Leiden mice decreases the VLDL particle production rate, as a consequence of a strongly reduced bile acid biosynthesis, leading to a decrease in plasma triglycerides. These data underscore the close relationship between bile acid biosynthesis and triglyceride levels. Chemicals / CAS: cholesterol 7alpha monooxygenase, 9037-53-0; cholesterol, 57-88-5; acyltransferase, 9012-30-0, 9054-54-0; alpha tocopherol, 1406-18-4, 1406-70-8, 52225-20-4, 58-95-7, 59-02-9; diacylglycerol acyltransferase, 9029-98-5; retinol, 68-26-8, 82445-97-4; Acyltransferases, EC 2.3.-; apolipoprotein E3 (Leidein); Apolipoprotein E3; Apolipoproteins B; Apolipoproteins E; Bile Acids and Salts; Cholesterol 7-alpha-Hydroxylase, EC 1.14.13.17; Cholesterol Esters; Dgat1 protein, mouse, EC 2.3.1.20; Diacylglycerol O-Acyltransferase, EC 2.3.1.20; Ketone Bodies; Lipoproteins, VLDL; RNA, Messenger; Sterols; Triglycerides; Vitamin A, 11103-57-4; Vitamin E, 1406-18-4