Confirmation, via in situ hybridization, of the occurrence of Robertsonian translocations during lemur evolution by localization of GLUDP1 DNA sequences on lemur chromosomes.

A human genomic DNA sequence derived from glutamate dehydrogenase pseudogene 1 was used as a probe for in situ hybridization to the chromosomes of three lemur species, Eulemur fulvus mayottensis (EFU), E. macaco macaco (EMA), and E. coronatus (ECO). This sequence, which is 98% homologous to the nucleotide sequence of the gene for human glutamate dehydrogenase (GLUD), was found on homologous bands of three morphologically similar chromosome segments, EFU14, EMA5p, and ECO8q, confirming that different Robertsonian translocations occurred during the evolution of these three species. These loci on the lemur chromosomes probably correspond to the human GLUD locus.     

Localization of a new highly repeated DNA sequence of Lemur cafta (Lemuridae, Strepsirhini).

We have isolated and cloned an 800-bp highly repeated DNA (HRDNA) sequence from Lemur catta (LCA) and described its localization on LCA chromosomes. Lemur catta HRDNA sequences were localized by performing FISH experiments on standard and elongated metaphasic chromosomes using an LCA HRDNA probe (LCASAT). A complex hybridization pattern was detected. A strong pericentromeric hybridization signal was observed on most LCA chromosomes. Chromosomes 7 and 13 were lit in pericentromeric regions, as well as in the interspersed heterochromatin. Chromosomes 1, 3, 4, 17, 19, X, and microchromosomes (20, 25, 26, and 27) showed no signals in the pericentromeric region, but chromosomes 3 and 4 showed a positive hybridization in heterochromatic regions. The 800-bp L catta HRDNA was species specific. We performed FISH experiments with the LCASAT probe on Eulemur macaco macaco (EMA) and Eulemur fulvus fulvus (EFU) metaphases and no positive signal of hybridization was detected. These findings were also confirmed by Southern blot analysis and PCR.     

Marking behaviour in two lemur species (L. fulvus and L. macaco): relation to social status, reproduction, aggression and environmental change.

The influence of social status, reproductive and agonistic contexts and environmental change on scent-marking and allomarking rates were studied in captive groups of Lemur fulvus and Lemur macaco. No evidence of female social dominance over males appeared in either species. In L. fulvus, intrasexual relationships were characterized by the dominance of one adult male over another and by the existence of female affiliative association ('central' vs. 'peripheral' females). In L. macaco, no intrasexual dominance relationships were apparent except for a brief ostracism of one female. In both species, (1) intrasexual differences in social status were related to differences in marking rates, (2) no direct relation appeared between marking rates and aggression or reproduction, (3) allomarking was not differentially directed towards specific individuals and (4) physical environmental factors clearly influenced scent-marking and allomarking rates. These results are discussed in relation to the possible functions of marking behaviour in intragroup relations.     

Stillborn triploid complex hybrid of lemurs (Eulemur macaco x E. coronatus)

The karyotype of a triploid lemur hybrid, issued from the backcross of an Eulemur macaco male with a female E. coronatus hybrid is reported. The differential negative effect of the multivalents on male and female fertility is discussed.     

Highly repeated DNA analysis and systematics of the Lemuridae,a family of Malagasy prosimians

Hybridization of highly repeated DNA sequences ofEulemur fulvus mayottensis, Lemur catta, andVarecia has been performed on blots of different species of Lemuridae (L. catta, Hapalemur griseus, Varecia variegata variegata, V. v. rubra, E. macaco macaco, E. coronatus, E. mongoz, andE. rubriventer). The probe ofE. fulvus only hybridized with the differentEulemur species, whereas that ofVarecia hybridized with the two subspecies ofVarecia and that ofL. catta with bothL. catta andHapalemur. These results were used to confirm the classification ofVarecia in a separate genus and to review the separation of theL. catta/Hapalemur group from the other species ofEulemur. Comparison of the migration patterns from DNA fragments of these different species has been used to propose a cladogram of the differentEulemur species.     

Learning set formation in slow lorises (Nycticebus coucang)

In primates, learning set formation has been reported in various simian species, but in only few prosimian species. The formation of visual discrimination learning set was tested on a nocturnal prosimian species, slow lorises (Nycticebus coucang). Their performance was higher than that of some New World monkeys. This confirmed the suggestion from the data on black lemurs (Lemur macaco) that there is an overlap between prosimians and simians in learning set ability.     

Distribution and morphological characters of intermediate forms between the black lemur (Eulemur macaco macaco) and the Sclater's lemur (E. m. flavifrons)

A study of intermediate forms betweenEulemur macaco macaco andE. m. flavifrons was performed on animals in different areas located to the north, south, and east of the known limits of distribution in Maromandia. A large hybridization zone was defined and morphological and dermatoglyphic comparisons were done on the different animals.     

A comparison of the reproductive cycle of three species of Lemur.

The duration of the luteal phase and the 'proestrus' phase in three species of lemurs (Lemur macaco, Lemur catta, and Lemur variegatus) was determined by serum progesterone measurement. Total immunoreactive estrogens were measured and remained below 0.20 ng/ml except for an apparent peak of short duration during estrus. Circulating testosterone levels in males confirm previously described seasonal gonadal function. The reproductive cycle of the female lemur is discussed and compared to the cycles of estrous and menstrual animals.     

Urinary Progestogen and Estrogen Excretion During Pregnancy in Eulemur macaco flavifrons,E. rubriventer,and Hapalemur griseus occidentalis

Via a non-invasive approach, we aimed to provide comparative data on the presence and relative abundance of progestogen and estrogen metabolites excreted into the urine of Eulemur rubriventer, E. macaco flavifrons and Hapalemur griseus occidentalis and to characterize the patterns of progestogen and estrogen excretion during pregnancy. We found that estrone is the major urinary estrogen in Eulemur macaco flavifrons and Hapalemur griseus occidentalis, while 16-hydroxyestrone appeared to be the predominant estrogen in the urine of E. rubriventer. Estradiol-17ß was either absent (Hapalemur) or present in very low amounts. HPLC of progestogens had high levels of immunoreactivity in an assay against 5-pregnane-3-ol-20-one (5-P-3OH) in each species, though the nature of the progestogens measured by the 5-P-3OH assay differed among species. During pregnancy, 5-P-3OH levels remained relatively low in Eulemur rubriventer, whereas in E. macaco flavifrons and Hapalemur griseus occidentalis, a sustained elevation in levels occurred from mid-pregnancy until the final weeks before parturition. Estrogen excretion differed depending on the sex of the fetus in each species, with only females carrying male infants showing clearly elevated estrogen levels during the last 6–8 weeks of gestation. In conclusion, we demonstrate both species similarities and differences in the metabolism and urinary excretion patterns of reproductive hormones throughout gestation in the Lemuridae. The data not only extend our knowledge on the reproductive physiology of lemurs but also show that more studies on other lemur taxa are needed to provide a broader basis for interspecific comparison.     

Demography, range use, and behavior in black lemurs (Eulemur macaco macaco) at Ampasikely, northwest Madagascar

We studied a black lemur population over a 2-year period (1992-1993) and 8 years later (2000) in a 50-ha secondary forest in northwest Madagascar. All of the animals were marked to investigate population dynamics and seasonal variation in ranging and behavior, and new data on black lemurs were obtained. Our data on demographic characteristics were expanded to include other forest sites and contrasted with those collected in other Eulemur macaco macaco field studies, in relation to human activity and the presence of introduced and cultivated plant species. Density is affected by deforestation and hunting. Group size and home range depend on the composition of the forest and probably food patches. Sex ratio at birth varies according to the number of females per group, a result that fits the local resource competition model. Groups are multimale-multifemale, and adult females form the core of the groups. Reproductive parameters indicate sharply defined seasonal breeding, a high female reproductive rate, and birth synchrony. Changes in group composition reveal male and female juvenile dispersal, male transfer between groups at the time of mating, and adult female transfer and group fission when groups exceed a critical size. At mating and birth, intergroup agonistic encounters occurred at home-range boundaries, and larger groups were dominant over smaller groups. Patterns of intragroup interactions suggest that males compete for access to groups of females during the mating season, and that females may compete for food resources during the birth season. Our study also reports female social dominance and lack of sexual weight dimorphism in this species.     

Chromosome variability in the Lemuridae

Chromosome studies have been conducted in Lemur catta, L. macaco, L. mongoz, L. fulvus fulvus, and a hybrid L. fulvus fulvus x L. fulvus albifrons. Comparative analysis shows that inter- and intraspecific chromosome variability is a common finding in Lemurs. The Lemuridae are divided into three groups according to the characteristics of their chromosome complement. A reclassification of L. catta with the Hapalemurs is suggested, based on chromosomal and nonchromosomal data.     

Chromosomal evolution in Malagasy lemurs. II. Meiosis in intra- and interspecific hybrids in the genus Lemur.

The chromosome analysis of meiosis in four lemurs, Lemur fulvus fulvus, L. f. collaris, L. f. albocollaris, and L. macaco, and particular hybrid crosses is reported. In metaphase I, trivalents and chain elements were detected and identified with T-banding. The study largely confirms our previous work on mitotic karyotype comparisons in the genus Lemur. The absence of chain multivalents elements in the pachytene stages of hybrid meiosis, where a chain is detected later in diakinesis, may offer evidence on the possible existence of a two-step pairing mechanism in meiotic homolog pairing. Considerations about the role of the chromosome rearrangements in establishing a gametic barrier in speciation are developed.     

Study of the antiviral activity of a poly I : poly-C complex with poly-L-lysine in monkeys]

Antiviral activity of poly-I-poly-C complex with poly-L-lysine was studied on macaco rhesus. The complex bifilamentous polyribonucleotide induced active production of serum interferon and provided pronounced protection of the monkeys infected intracutaneously with the variolovaccine virus (10 LD50 for the monkeys in intracutaneous infection). The effectiveness of the protective effect depended on the scheme and route of the drug administration. The highest prophylactic and therapeutic effect was provided by local administration of the complex in a dose of I mg per I kg of the body weight, the incubation period being increased 2--3 times and the period of the skin affections being decreased approximately 2 times. The results of the studies on the effect of poly-I-poly-C complex with poly-L-lysine were evident of definite prophylactic activity of the drug against experimental vernal encephalitis in the monkeys. The animals not treated with the inductor died on the 16th or 17th day after infection because of the paralysis of the trunc and extremities muscles. The clinical evidences of the disease in the animals treated with the drug were not uniform: from complete health to death.     

Phylogenetic relationships among Lemuridae (Primates): evidence from mtDNA

The family Lemuridae includes four genera: Eulemur, Hapalemur, Lemur,Varecia. Taxonomy and phylogenetic relationships between L. catta, Eulemur and Hapalemur, and of Varecia to these other lemurids, continue to be hotly debated. Nodal relationships among the five Eulemur species also remain contentious. A mitochondrial DNA sequence dataset from the ND 3, ND 4 L, ND 4 genes and five tRNAs (Gly, Arg, His, Ser, Leu) was generated to try to clarify phylogenetic relationships w ithin the Lemuridae. Samples (n=39) from all ten lemurid species were collected and analysed. Three Daubentonia madagascariensis were included as outgroup taxa. The approximately 2400 bp sequences were analysed using maximum parsimony, neighbor-joining and maximum likelihood methods. The results support monophyly of Eulemur, a basal divergence of Varecia, and a sister-group relationship for Lemur/Hapalemur. Based on tree topology, bootstrap values, and pairwise distance comparisons, we conclude thatVarecia and Eulemur both represent distinct genera separate from L. catta. H. griseus andH. aureus form a clade with strong support, but the sequence data do not permit robust resolution of the trichotomy involving H. simus, H. aureus/H. griseus and L. catta. Within Eulemur there is strong support for a clade containing E. fulvus, E. mongoz and E. rubriventer. However, analyses failed to clearly resolve relationships among those three species or with the more distantly related E. coronatus and E. macaco. Our sequencing data support the current subspecific status of E.m. macaco and E.m. flavifrons, and that of V.v. variegata and V.v. rubra. However, tree topology and relatively large genetic distances among individual V.v. variegata indicate that there may be more phylogenetic structure within this taxon than is indicated by current taxonomy.     

Genetic Variation in Prosimian Species

Scheffrahn et al. (1998a,b) aimed to outline the possible contributions of genetics to conservation biology: the determination of genetic variation of wild groups and its use as a guideline in breeding programs. Unfortunately, the amount of genetic variation within wild groups of nonhuman primates is rarely known. In particular, this observation holds for prosimians. Average heterozygosity is widely considered to be a good indicator of the magnitude of intraspecific variation. We provide some values of average heterozygosity of wild populations of Otolemur garnettii, Eulemur macaco macaco and E. m. flavifrons.     

Brief communication: Blue eyes in lemurs and humans: Same phenotype,different genetic mechanism

Almost all mammals have brown or darkly‐pigmented eyes (irises), but among primates, there are some prominent blue‐eyed exceptions. The blue eyes of some humans and lemurs are a striking example of convergent evolution of a rare phenotype on distant branches of the primate tree. Recent work on humans indicates that blue eye color is associated with, and likely caused by, a single nucleotide polymorphism (rs12913832) in an intron of the gene HERC2, which likely regulates expression of the neighboring pigmentation gene OCA2. This raises the immediate question of whether blue eyes in lemurs might have a similar genetic basis. We addressed this by sequencing the homologous genetic region in the blue‐eyed black lemur (Eulemur macaco flavifrons; N = 4) and the closely‐related black lemur (Eulemur macaco macaco; N = 4), which has brown eyes. We then compared a 166‐bp segment corresponding to and flanking the human eye‐color‐associated region in these lemurs, as well as other primates (human, chimpanzee, orangutan, macaque, ring‐tailed lemur, mouse lemur). Aligned sequences indicated that this region is strongly conserved in both Eulemur macaco subspecies as well as the other primates (except blue‐eyed humans). Therefore, it is unlikely that this regulatory segment plays a major role in eye color differences among lemurs as it does in humans. Although convergent phenotypes can sometimes come about via the same or similar genetic changes occurring independently, this does not seem to be the case here, as we have shown that the genetic basis of blue eyes in lemurs differs from that of humans. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Trypanosoma cruzi prevalence and epidemiologic trends in lemurs on St. Catherines Island, Georgia

Lemurs on St. Catherines Island, Georgia were tested for Trypanosoma cruzi infection to develop a better understanding of the epizootiology of the parasite in nonhuman primates in the southeastern United States. Fifty-six ring-tailed (Lemur catta), blue-eyed black (Eulemur macaco flavifrons), and black-and-white ruffed (Varecia variegata variegata) lemurs were tested by hemoculture and serology to determine the prevalence of T. cruzi in the population. Of those tested 3 (5%) were identified as culture positive and 25 (44.6%) as seropositive. When hemoculture results were compared with those from a similar study performed in 1997, prevalence remained unchanged. Genetic characterization of the 3 culture isolates indicated they belong to the T. cruzi IIa group, which is identical to strains previously isolated from raccoons on the island. Despite the occurrence of T. cruzi in the population, there was no evidence that the health of the lemurs was compromised as a result of infection. Based upon prevalence and available breeding records we speculate that both vertical and vector-mediated transmission play significant roles in the epidemiology of T. cruzi on the island. This also represents the first report of autochthonous infection in blue-eyed black and black-and-white ruffed lemurs.     

Genetic comparison between different populations of Eulemur macaco flavifrons in northwest Madagascar using RAPD markers

Eulemur macaco flavifrons, the Sclater's black lemur, is a critically endangered subspecies of northwest Madagascar, which is not yet protected by any reserve. In order to study the feasibility of creating such a reserve, an area of outstanding biological importance was selected in the region of Maromandia-Sahamalaza, which is probably the only remaining place which would permit the long-term survival of the Sclater's black lemur. To determine if genetic management is needed for the Sahamalaza black lemur population, its genetic variability was estimated with random amplified polymorphic DNA (RAPD) markers and compared with other populations. These comparisons demonstrate that the Sahamalaza black lemurs have a genetic variability equivalent to those in other areas. Thus, we conclude that no genetic management is required at the present time.     

Factors affecting offspring survival and development in a cooperative bird: social, maternal and environmental effects

1. In many noncooperative vertebrates, maternal effects commonly influence offspring survival and development. In cooperative vertebrates, where multiple adults help to raise young from a single brood, social effects may reduce or replace maternal effects on offspring. 2. Factors affecting offspring survival and development at different stages (fledging, nutritional independence and adulthood) were tested in the cooperatively breeding Arabian babbler to determine the relative importance of social, maternal and environmental factors at each stage. An influence of maternal effects was found during the nestling stage only. 3. Social factors affected the survival and development of young at all stages. The amount of food received from helpers influenced post-fledging weight gain, development of foraging skills, and survival to reproductive age. Environmental effects were also important, with groups occupying high-quality territories more likely to produce young that survived to maturity. 4. The strong influence of helper contributions on the survival and development of young at all stages from hatching to maturity suggests social factors may have important long-term effects on offspring fitness in cooperative societies. Traditional measures of offspring survival in cooperative birds, which commonly measure survival to fledging age only, may underestimate the significant benefit of helper contributions on the survival and development of young.