Genetic management of captive prosimian populations,a report of experience withLoris tardigradus

Extinction of small, closed populations in captivity as well as in the wild is believed to be nearly inevitable, because inbreeding will adversely effect reproductive success, mortality, sex ratio and also the susceptibility to epidemic diseases and environmental stress. An ever increasing number of primate species exist only in small isolated populations, which contain only a part of the original genetic variability. In captive breeding programs research about genetic management strategies is, therefore, of essential importance. In 1980 we imported 9Loris tardigrdus nordicus (4 females, 5 males) from NE-Sri Lanka. The founders came from one natural breeding population. All sexual mature females are breeding. Up to now the colony contains 36 living individuals. The main goal of our long-term genetic management plan was to minimize inbreeding and to preserve the genetic diversity. Therefore, we try to pass the founder bottleneck rapidly by enlarging the population to a desired minimum population size of 25 pairs and to equalize the founder representation within any generation. The need to control the spread of sublethal genes, introduced by one of the founders, conflicts directly with the aim of equalizing the founder representation. A solution of this problem is discussed. To produce a sufficiently large population we intend to give animals to other institutions and to build up an exchange-system for offspring individuals, which should lead to an international studbook.     

A genetic evaluation of relatedness for broodstock management of captive,endangered Snake River sockeye salmon, <Emphasis Type="Italic">Oncorhynchus nerka</Emphasis>

The use of captive broodstocks is becoming more frequently employed as the number of species facing endangerment or extinction throughout the world increases. Efforts to rebuild the endangered Snake River sockeye salmon, Oncorhynchus nerka, population have been ongoing for over a decade, but the use of microsatellite data to develop inbreeding avoidance matrices is a more recent component to the program. This study used known genealogical relationships among sockeye salmon offspring to test four different pairwise relatedness estimators and a maximum-likelihood (M-L) relatedness estimator. The goal of this study was to develop a breeding strategy with these estimators that would minimize the loss of genetic diversity, minimize inbreeding, and determine how returning anadromous adults are incorporated into the broodstock along with full-term hatchery adults. Results of this study indicated that both the M _xy and R _QG estimators had the lowest Type II error rates and the M-L and R _R estimators had the lowest Type I error rates. An approach that utilizes a combination of estimators may provide the most valuable information for managers. We recommend that the M-L and R _R methods be used to rank the genetic importance of returning adults and the M _xy or R _QG estimators be used to determine which fish to pair for spawning. This approach provides for the best genetic management of this captive, endangered population and should be generally applicable to the genetic management of other endangered stocks with no pedigree.     

Effects of sociosexual environment on serum testosterone in captive male African rhinoceros

The relationships between testosterone concentrations in male African rhinoceros and the presence of conspecific males and females were investigated. Serum testosterone concentrations were measured using enzyme-linked immunoassay (EIA) in 37 male black rhinoceros (Diceros bicornis) and 21 male white rhinoceros (Ceratotherium simum) housed at 37 institutions in the USA. Testosterone concentrations in both black (n = 37) and white (n = 21) rhinoceros males rose with increasing numbers of females present (P < 0.05). Average testosterone concentrations also rose with an increased number of conspecific males (n = 34) in black rhinoceros (P < 0.05). However, no specific pattern was found among male white rhinoceros housed with other males. We inferred that introduction of females to a male may play an important role in stimulating libido and spermatogenesis. The similar response of black rhinoceros and white rhinoceros to increased numbers of females suggested that, at least historically, herd structure for blacks may have been more similar to whites than previously realized, and should be investigated further.     

Genetic assessment of the Iberian wolf Canis lupus signatus captive breeding program

The main goal of ex situ conservation programs is to improve the chances of long term survival of natural populations by founding and managing captive colonies that can serve as a source of individuals for future reintroductions or to reinforce existing populations. The degree in which a captive breeding program has captured the genetic diversity existing in the source wild population has seldom been evaluated. In this study we evaluate the genetic diversity in wild and captive populations of the Iberian wolf, Canis lupus signatus, in order to assess how much genetic diversity is being preserved in the ongoing ex situ conservation program for this subspecies. A sample of domestic dogs was also included in the analysis for comparison. Seventy-four wolves and 135 dogs were genotyped at 13 unlinked microsatellite loci. The results show that genetic diversity in Iberian wolves is comparable in magnitude to that of other wild populations of gray wolf. Both the wild and the captive Iberian wolf populations have a similarly high genetic diversity indicating that no substantial loss of diversity has occurred in the captive-breeding program. The effective number of founders of the program was estimated as ∼ ∼16, suggesting that all founders in the studbook pedigree were genetically independent. Our results emphasize also the genetic divergence between wolves and domestic dogs and indicate that our set of 13 microsatellite loci provide a powerful diagnostic test to distinguish wolves, dogs and their hybrids.     

Study of the variability of erythrocyte enzymes in captive and wild populations of the black lemur (Eulemur macaco macaco). An indispensable preliminary in captive breeding programmes

A study of ten erythrocyte enzymes (PGM I, II, III, G6PD, 6PGD, GLO I, ADA, Est D, DIA, AcP, CA II, and AK) performed on 89 wild and 32 captiveEulemur macaco macaco shows that most systems are monomorphic except four (GLO I, CA II, 6PGD, and NADH DIA). The polymorphism of these markers allows us to make a satisfactory analysis of the variability on this species, especially on the view of comparing wild and captive populations, and shows that: (1) the population does not contain all phenotypes existing in the wild CA_a, CA_{a + b}, DIA_IV, GLO I_{B − C}, and PGD_c are completely absent in all captive populations and DIA_{III + IV} is only present in three out of 32 animals; (2) in the Nosy-komba Island, the PGD_c and DIA_IV are absent and DIA_{III + IV} and GLO I_{B − C} are only present in 1 out of 46 analyzed samples, showing that this population constitutes an isolate. The possibility to use these data for a strategy of Lemur conservation is discussed.     

Evaluating ex situ conservation projects: Genetic structure of the captive population of the Arabian sand cat

Ex situ conservation plays an increasingly important role in the conservation of endangered species. Molecular genetic markers can be helpful to assess the status of captive breeding programmes. We present the first molecular genetic analysis of the captive population of the Arabian sand cat (Felis margarita harrisoni) using microsatellites. Our data indicates that the captive population of F. m. harrisoni comprises three genetic clusters, which are based on different founder lineages. Genetic diversity was relatively high, the effective population size even exceeded the number of founders. This was presumably caused by subsequently integrating unrelated, genetically diverse founders into the captive population and a careful management based on minimizing kinship. However, we detected an error in the studbook records, which might have led to incestuous matings and underlines the usefulness of molecular evaluations in captive breeding programmes for endangered species.     

The role of zoos and captive breeding in lemur conservation

All the lemurs of Madagascar are declining in the wild, but the species and numbers held in collections outside Madagascar are not sufficient to ensure the continuence of their genetic diversity in captivity. General recommendations as to how to rectify this situation are presented, including a strong plea for coordinated population management among collections holding lemurs.     

Preservation of genetic diversity in a wild and captive population of a rapidly declining mammal,the Common hamster of the French Alsace region

The Common hamster (Cricetus cricetus) faced massive population declines throughout its western range margin. In France, relict populations remained in the Alsace region. By comparing allelic diversity using microsatellite analysis over a time span of 12 years we investigated if this population decline led to genetic erosion in a French relict population of the species. Genetic diversity was moderate but comparable to other populations from Western Europe. Interestingly, no decline of allelic variation was revealed between 1999 and 2012 in the study region (expected heterozygosity = 0.51 in 1999 and 0.5 in 2012, respectively), suggesting a sufficiently high effective population size of ∼500 (179–956 SD). While several alleles were lost in a captive breed maintained for restocking purposes in the region, expected heterozygosity was comparably high (=0.5). Our results show that genetic diversity has been effectively maintained in a relict population of French Common hamsters despite of massive range loss. We recommend the maintenance of intense in situ conservation effort, along with regular monitoring of genetic diversity and effective population size.     

Carry-over effect of captive breeding reduces reproductive fitness of wild-born descendants in the wild

Supplementation of wild populations with captive-bred organisms is a common practice for conservation of threatened wild populations. Yet it is largely unknown whether such programmes actually help population size recovery. While a negative genetic effect of captive breeding that decreases fitness of captive-bred organisms has been detected, there is no direct evidence for a carry-over effect of captive breeding in their wild-born descendants, which would drag down the fitness of the wild population in subsequent generations. In this study, we use genetic parentage assignments to reconstruct a pedigree and estimate reproductive fitness of the wild-born descendants of captive-bred parents in a supplemented population of steelhead trout (Oncorhynchus mykiss). The estimated fitness varied among years, but overall relative reproductive fitness was only 37 per cent in wild-born fish from two captive-bred parents and 87 per cent in those from one captive-bred and one wild parent (relative to those from two wild parents). Our results suggest a significant carry-over effect of captive breeding, which has negative influence on the size of the wild population in the generation after supplementation. In this population, the population fitness could have been 8 per cent higher if there was no carry-over effect during the study period.     

1. The importance of genetic resources in plant breeding

Modern agricultural technology and the introduction of new high-yielding varieties are largely eliminating the wide range of crop genetic diversity that has evolved during the five to ten thousand years since food plants were first domesticated. Related wild species are also on the decline because of new land use policies. These gene pools (or what is left of them) are generally spoken of as genetic resources, and are vitally needed in the creation of new crop varieties by plant breeders. Wild species and land races often furnish genes conferring resistance to diseases and pests and adaptation to environmental stresses which cannot be found in the modern crop varieties.
The study of genetic diversity of crops, its storage in gene banks or in natural reserves, its evaluation and enhancement, are briefly described. The genetic resources work of the Food and Agriculture Organisation of the United Nations (FAO) and other international agencies such as the International Board for Plant Genetic Resources (IBPGR) is outlined.     

Molecular breeding strategies for the modification of lipid composition

Summary Lipids are key components of all living cells. Acyl lipids and sterols provide the matrix of the biological membranes that both define the boundaries of cells and organelles, and act as sites for the trafficking of molecules within and into/out of cells. Lipids are also important metabolic intermediates and the most efficient form of energy storage that is available to a cell. It is the latter, energy-storing function that is of most relevance to this review. Storage lipids are accumulated in abundance in many of our most important crops, including maize, soybean, rapeseed, and oil palm, giving rise to a commerical sector valued at over $50 billion/year. Because the storage lipids of the major global oil crops have a relatively restricted composition, there is great interest in using all available breeding technologies, whether traditional or modern, to enhance the variation in lipid quality in existing crops and/or to domesticate new crops that already accumulate useful novel lipids. Over the past few decades, there has been a great deal of effort to manipulate fatty acid composition in order to produce novel lipids, especially for industrial applications. However, these attempts, many based on genetic engineering, have met with only limited commercial success-to date. More recently, there has been a resurgence of interest in the modification of both acyl and non-acyl lipids to enhance the nutritional quality of plant oils. In this review, we will examine the background to plant lipid modification and some of the latest developments, with a particular focus on edible oils.     

Capital and income breeding and the evolution of colony founding strategies in ants

Ability to store resources that will be used for reproduction represents a potential life history adaptation because storage permits feeding and reproduction to be decoupled spatially and/or temporally. The two ends of a continuum involve acquiring all resources prior to reproduction (capital breeding) or acquiring all resources during the reproductive period (income breeding). Traditional life history theory examines tradeoffs between costs and benefits of such strategies, but this theory has not been integrated into life history studies of ants, even though founding queens have the analogous strategies of fully claustral (capital breeding) and semi-claustral (income breeding). This study demonstrates that facultatively semi-claustral queens of the seed-harvester ant Pogonomyrmex desertorum exhibit phenotypic plasticity during colony founding because unfed queens produced few, small minims, whereas ad libitum fed queens produced larger, heavier minims and additional brood. Fed queens also lost less mass than unfed queens despite their producing more brood. Overall, foraging provides queens with a suite of benefits that likely offset potential negative effects of foraging risk. Life history studies across a diverse array of taxa show that capital breeding is consistently associated with low availability and/or unpredictability of food, i.e., environmental conditions that favor prepackaging of reproductive resources. Such a broad and consistent pattern suggests that similar factors favored the evolution of fully claustral (capital breeding) colony founding in ants. Overall, these data suggest that ant researchers should revise their conventional view that fully claustral colony founding evolved because it eliminated the need for queens to leave the nest to forage. Instead, colony founding strategies should be examined from the perspective of environmental variation, i.e., availability and predictability of food. I also provide a functional scenario that could explain the evolution of colony founding strategies in ants. Received 16 November 2005; revised 1 March 2006; accepted 29 March 2006.     

杂合子长期变化的计算机模拟试验——群体中长期保存杂合子的可能性分析

本文运用计算机模拟的方法,在随机交配、随机留种的情况下,分析了群体中长期保存杂合子的可能性。从模拟试验结果验证了群体遗传学理论的一个重要结论:群体中长期保存杂合子是不可能的。因此在畜禽保种工作中以减少基因纯合而保存群体全部基因为目的,来控制近交是不一定必要的。     

缅甸蟒线粒体Cytb基因遗传多样性分析

为了探讨海南文昌种蟒养殖基地的种蟒的遗传多样性和个体来源,本研究对27条种蟒的细胞色素b基因的全序列进行了测定和分析。结果表明:缅甸蟒cytb基因全长1 111 bp,序列中A+T含量为58.0%,G+C含量为42.0%,单倍型多样性(Hd)为(0.755±0.053),核苷酸多样性(Pi)为(0.003 29±0.000 43),表明该种群遗传多样性较高。共检测出6条单倍型,单倍型间遗传距离最大为0.007,最小为0.001;与已知地理来源的个体构建系统发育树显示,该养殖种群来源两个母系世系。本研究结果为制定缅甸蟒合理圈养计划和科学放归提供理论基础。     

The re-stocking of captive-bred ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve, Madagascar: methodology and recommendations

Since November 1997 the Madagascar Fauna Group has released 13 captive-bred black and white ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve in eastern Madagascar. The release programme has three major aims: (1) to assess the ability of captive-bred V. v. variegata to adapt to life in their natural habitat; (2) to investigate the contribution that such a release programme can make to reinforcing the existing small wild population of V. v. variegata in Betampona; and (3) to contribute to the long-term protection and conservation of the reserve. Criteria for the selection of release candidates, veterinary screening and pre-release experience in naturalistic environments are described and discussed. Methods for post-release monitoring of health and behaviour are covered in detail. The importance of considering the social dynamics of the species involved is emphasised. The survival of five of the releasees, plus successful reproduction and integration with the wild population have led to the conclusion that the release was a success.     

Effects of various breeding strategies on diploid drone frequency and quantitative traits in a honey bee population

When selecting in a finite population of honeybees there is a conflict between gain in a quantitative trait and increasing homozygosity, and therefore the frequency of inviable diploid drones. The consequences when using different mating, import, and selection strategies on diploid drone frequency and genetic gain, was explored with Monte Carlo computer simulations.Within a closed population breeding structure, mass selection gave the highest genetic gain in the quantitative trait, but also the largest increase in percentage diploid drones and queens with unacceptably-low brood viability. Mass selection combined with truncation selection against queens having more than 15% diploid drones gave a comparable genetic gain and was the best strategy of the ones studied to avoid diploid drones. Within-family selection (one replacement per sib group) gave the least genetic gain, and a frequency of diploid drones comparable to random (no) selection. It was intermediate between mass selection and mass selection combined with viability selection concerning the frequency of diploid drones.Insemination with pooled and homogenized semen originating from all breeder queens (30), as compared to natural mating with 12 randomly-selected drones, had little effect on the genetic gain and on the overall frequency of diploid drones (10 to 15% by generation 20).The effect of opening the closed breeding population for the import of external queens every generation, by exchanging breeder queens of lowest performance with a corresponding number of new queens (5, 10and 15 out of 30), was also investigated. Under mass selection (natural mating as well as artificial insemination) the frequency of diploid drones and the proportion of queens discarded were reduced because of low brood viability. However, artificial insemination was superior to natural mating considering the latter criterion. If the imported queens were at the same genetic level for the quantitative trait under selection as the whole breeding population at that generation, or 10% better, the genetic gain was respectively slightly reduced and approximately maintained. If the imported queens were of inferior quality (equal to the initial population) the import of queens slowed genetic progress considerably.     

Agonistic and grooming behavior of captive crowned lemurs (Lemur coronatus) during the breeding season

Captive breeding of rare and endangered prosimians may be enhanced by an increased understanding of all aspects of their seasonal mating behavior. In this study, the agonistic and grooming behaior of captiveL. coronatus were studied during their annual breeding season. Between October and March, selected aspects of agonistic and grooming behavior of four male-female groups were recorded. Males initiated significantly more allogrooming than females. The frequency of this behavior pattern increased significantly in the weeks of estrus. Females performed significantly more agonistic behavior patterns than males. The mean frequency of agonistic interactions decreased significantly during the breeding season. In successfully reproducing groups males showed much less agonism towards females, than they did in unsuccessful groups. Inter-specific comparisons demonstrated that the patterns of agonistic interactions during the breeding season are very different among closely related species of lemurids. The conclusions drawn from this study are that captive breeding of crowned lemurs may be enhanced by keeping permanent multi-male, multi-female groups.