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.     

华南虎圈养种群的统计分析

对《华南虎谱系》307 只登录个体的统计表明, 其圈养的历史有46 年。在人工繁殖的38 年中产122 胎287仔。现存圈养华南虎分散在全国22 家单位, 有57 只个体, 性比M∶F = 1185 , 能成功繁殖后代的个体仅5 只(只占818 %) , 是一个衰退的种群。通过SPARKS 和GENES 软件分析发现: 从1977 年开始, 圈养种群的基因多样性便逐渐下降而近交系数却不断增加。     

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.     

实验室条件下达乌尔黄鼠的越冬繁殖

达乌尔黄鼠（Spermophilusdauricus）是国内研究冬眠生理学的主要模式动物,且日益为医学研究所关注。实验室条件下繁殖种群具有明确生活史特征,是相关研究的理想对象,但以往研究中,达乌尔黄鼠实验室条件下繁殖成功率及后代成活率均很低。本研究通过采取丰富饲料种类、雄性出眠后的暖温暂养、“双笼配对”等措施,对实验室条件下越冬达乌尔黄鼠进行配对,从21对动物中成功繁殖出18窝子代,繁殖成功率85.7 %。78只子代饲养至3月龄,仍有67只存活,存活率为85.9 %。通过本实验,得出改进达乌尔黄鼠实验室条件下繁殖的主要措施如下：（1）繁殖期母鼠及发育期幼鼠,除饲喂标准大鼠饲料外,适量添加幼犬粮、胡萝卜,以补充营养;（2）出眠的雄性达乌尔黄鼠放入18℃房间暂养2周,有助于其性腺发育,促进繁殖成功;（3）“双笼配对”能有效地降低外界干扰,减少动物的杀婴行为。       

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.     

First captive breeding of the imperial parrot (Amazona imperialis)

We describe the rearing and development of the first imperial parrot (Amazona imperialis) hatched and raised in captivity. A single egg was hen-incubated for 28 days, and the chick was parent-fed for ～14 days, after which it was removed for hand-rearing. Similar to wild, parent-reared imperial nestlings, the chick developed fully within 12 weeks, weaning at 540 g body weight. Endangered and endemic to Dominica, the imperial is a vital flagship for oceanic rainforest conservation. Chronicling the neonatal development of A. imperialis helps illuminate the natural history of this enigmatic species, whose secretive nesting habits and low population density have frustrated a detailed understanding of its ecology and reproduction.     

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.     

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.     

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.     

Mitochondrial DNA analysis reveals hidden genetic diversity in captive populations of the threatened American crocodile (Crocodylus acutus) in Colombia

Identification of units within species worthy of separate management consideration is an important area within conservation. Mitochondrial DNA (mtDNA) surveys can potentially contribute to this by identifying phylogenetic and population structure below the species level. The American crocodile (Crocodylus acutus) is broadly distributed throughout the Neotropics. Its numbers have been reduced severely with the species threatened throughout much of its distribution. In Colombia, the release of individuals from commercial captive populations has emerged as a possible conservation strategy that could contribute to species recovery. However, no studies have addressed levels of genetic differentiation or diversity within C. acutus in Colombia, thus complicating conservation and management decisions. Here, sequence variation was studied in mtDNA cytochrome b and cytochrome oxidase I gene sequences in three Colombian captive populations of C. acutus. Two distinct lineages were identified: C. acutus‐I, corresponding to haplotypes from Colombia and closely related Central American haplotypes; and C. acutus‐II, corresponding to all remaining haplotypes from Colombia. Comparison with findings from other studies indicates the presence of a single “northern” lineage (corresponding to C. acutus‐I) distributed from North America (southern Florida), through Central America and into northern South America. The absence of C. acutus‐II haplotypes from North and Central America indicates that the C. acutus‐II lineage probably represents a separate South American lineage. There appears to be sufficient divergence between lineages to suggest that they could represent two distinct evolutionary units. We suggest that this differentiation needs to be recognized for conservation purposes because it clearly contributes to the overall genetic diversity of the species. All Colombian captive populations included in this study contained a mixture of representatives of both lineages. As such, we recommend against the use of captive‐bred individuals for conservation strategies until further genetic information is available.     

Impact of selection and breeding on the genetic diversity in Douglas-fir

Genetic changes following domestication of Douglas-fir were studied using isozyme data derived from two generations of seed orchards and their 49 wild progenitor populations. In addition, the breeding, production, and infusion populations used in the seed orchards were compared to their wild counterparts. Several parameters of gene diversity were measured (number of alleles per locus N _a, per cent of polymorphic loci PLP, and expected heterozygosity H, and population divergence D). These measures were similar or higher in the domesticated populations compared to their natural progenitors, indicating that early selection and breeding of a highly polymorphic species does not significantly reduce genetic variation. The two generations of seed orchards also did not differ, indicating that genetic variation may remain stable over future generations of forest plantations. Interestingly, compared to the natural populations, heterozygosity was higher in the seed orchards, probably due to pooling of widely distributed natural populations; however, rare localized or private alleles seemed to be less frequent in the domesticated populations. Differentiation values were not significant between the first generation orchards and the natural populations, but significant differences were observed between the second generation orchards and the wild progenitor populations, probably due to the interbreeding that forms the advanced generation seed orchards.     

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.     

Development of husbandry practices for the captive breeding of key largo woodrats (Neotoma floridana smalli)

The Key Largo woodrat is an endangered rodent endemic to the island of Key Largo in the Florida Keys. After several reports documented a steep decline in the population, the US Fish and Wildlife Service developed a recovery plan, including captive breeding and reintroduction. Captive breeding efforts were to be focused on providing animals for future reintroduction to protected areas on Key Largo. However, little was known about the husbandry needs or reproductive behavior of this elusive nocturnal species. In 2005, Disney's Animal Kingdom^® received 11 animals and began to systematically investigate methods of breeding Key Largo woodrats. Since the program's inception, 30 pups have been born and successfully parent reared. In this report, we describe some of the husbandry techniques that have contributed to the success of the Key Largo woodrat captive breeding program at Disney's Animal Kingdom^®. The results obtained may be of use to other facilities maintaining woodrats and other rodent species. Zoo Biol 30:318–327, 2011. © 2010 Wiley‐Liss, Inc.