Unresolved molecular phylogenies of gibbons and siamangs (Family: Hylobatidae) based on mitochondrial, Y-linked, and X-linked loci indicate a rapid Miocene radiation or sudden vicariance event.

According to recent taxonomic reclassification, the primate family Hylobatidae contains four genera (Hoolock, Nomascus, Symphalangus, and Hylobates) and between 14 and 18 species, making it by far the most species-rich group of extant hominoids. Known as the "small apes", these small arboreal primates are distributed throughout Southeast, South and East Asia. Considerable uncertainty surrounds the phylogeny of extant hylobatids, particularly the relationships among the genera and the species within the Hylobates genus. In this paper we use parsimony, likelihood, and Bayesian methods to analyze a dataset containing nearly 14 kilobase pairs, which includes newly collected sequences from X-linked, Y-linked, and mitochondrial loci together with data from previous mitochondrial studies. Parsimony, likelihood, and Bayesian analyses largely failed to find a significant difference among phylogenies with any of the four genera as the most basal taxon. All analyses, however, support a tree with Hylobates and Symphalangus as most closely related genera. One strongly supported phylogenetic result within the Hylobates genus is that Hylobates pileatus is the most basal taxon. Multiple analyses failed to find significant support for any singular genus-level phylogeny. While it is natural to suspect that there might not be sufficient data for phylogenetic resolution (whenever that situation occurs), an alternative hypothesis relating to the nature of gibbon speciation exists. This lack of resolution may be the result of a rapid radiation or a sudden vicariance event of the hylobatid genera, and it is likely that a similarly rapid radiation occurred within the Hylobates genus. Additional molecular and paleontological evidence are necessary to better test among these, and other, hypotheses of hylobatid evolution.

Complex, compound inversion/translocation polymorphism in an ape: presumptive intermediate stage in the karyotypic evolution of the agile gibbon Hylobates agilis.

Karyotypic variation in five gibbon species of the subgenus Hylobates (2n = 44) was assessed in 63 animals, 23 of them wild born. Acquisition of key specimens of Hylobates agilis (agile gibbon), whose karyotype had been problematic due to unresolved structural polymorphisms, led to disclosure of a compound inversion/translocation polymorphism. A polymorphic region of chromosome 8 harboring two pericentric inversions, one nested within the other, was in turn bissected by one breakpoint of a reciprocal translocation. In double-inversion + translocation heterozygotes, the theoretical meiotic pairing configuration is a double inversion loop, with four arms of a translocation quadrivalent radiating from the loop. Electron-microscopic analysis of synaptonemal complex configurations consistently revealed translocation quadrivalents but no inversion loops. Rather, nonhomologous pairing was evident in the inverted region, a condition that should preclude crossing over and the subsequent production of duplication-deficiency gametes. This is corroborated by the existence of normal offspring of compound heterozygotes, indicating that fertility may not be reduced despite the topological complexity of this polymorphic system. The distribution of inversion and translocation morphs in these taxa suggests application of cytogenetics in identifying gibbon specimens and avoiding undesirable hybridization in captive breeding efforts.

Procedures utilized for primate import quarantine at the International Center for Gibbon Studies.

The intent of the Foreign Quarantine requirements (42 CFR 71.53) for nonhuman primates (NHPs) is to prevent the importation of potentially serious infectious diseases that are not endemic to the United States. In 1990, prompted by an outbreak of Ebola (Reston) hemorrhagic fever at an (NHP) quarantine facility, the Centers for Disease Control and Prevention (CDC) initiated unannounced inspections of all NHP importers' quarantine facilities. During the inspections, the majority did not meet the required infection control and containment standards. Numerous discrepancies were identified in infection control and NHP quarantine protocols. Zoos should have knowledge of CDC requirements and recommendations for the importation of NHPs into the United States. Zoos planning to import NHPs should register with the CDC and have their NHP quarantine facility and protocols inspected and approved by CDC's Division of Quarantine. Specific areas addressed must include protocols for in-transit shipping and handling, transport to the quarantine facility, biocontainment procedures (transfer of NHPs from shipping containers to quarantine cages, entering/exiting the quarantine room, routine daily and emergency procedures, protective clothing, infection control, infectious waste disposal), occupational health, and employee training. Here, we provide information on the approved protocols used for import quarantine at a single registered importer facility specializing in importation of gibbons (Hylobatidae) for species conservation purposes. These procedures are site specific and are not intended to be applicable to the needs of all NHP import facilities.

Isolation of a herpes simplex virus type 1-like agent from the brain of a mountain agile gibbon (Hylobates agilis agilis) with encephalitis.

A captive-born 2-yr-old male mountain agile gibbon (Hylobates agilis agilis) that died of encephalitis harbored a herpes simplex virus type 1 (HSV1)-like agent in the brain. A complete necropsy revealed intensive meningeal congestion with nonsuppurative encephalitis. The virus was recovered from frozen brain tissue in Vero cells. The isolate was very similar but not identical to human HSV1. Both western blot assay and virus neutralization tests were done with sera from 15 gibbons. Antibodies against HSV1 and herpes simplex virus type 2 (HSV2) were detected in four healthy gibbons, which included four species in three subgenera.

Sexual behavior of maternally separated gibbons (Hylobates).

The effect of early maternal separation on the sexual behavior of captive gibbons was investigated because (a) maternal separation compromises sexual behavior of some nonhuman primates and (b) adequate sexual behavior is essential to species propagation. Most of the maternally separated gibbons (24/31) were sexually proficient. Sexual behavior overall did not differ significantly in relation to species, sex, origin (wild-vs. captive-born), or type of rearing facility (home vs. zoo). Sexual proficiency was not related to the age at separation from the mother, but it was associated with introduction within 19 months of age to a conspecific of less than 3 years of age and an absolute age difference of less than 2 years. Sexual proficiency was associated with rearing and adult housing in relatively large enclosures. Gibbons that were isolated from conspecifics between 6 months and 2 years of age were strongly attached to humans, but this did not prevent sexual proficiency. A greater proportion of males than females were adversely affected sexually by prolonged early social isolation. Inadequate sexual behavior was associated with fearfulness of conspecifics, which probably interfered with compatible social relationships, including duetting. Inadequate sexual behavior was but one aspect of a more general behavioral deficiency resulting from inadequate early socialization. Early maternal separation in gibbons is compatible with species-typical sexual behavior under the conditions described above. It is not necessary for gibbons to learn sexual and parental behavior by observing experienced adult conspecifics.