Activity pattern of the masked titi monkey,Callicebus personatus

A group of six masked titi monkeys was studied at the Sooretama Biological Reserve, Espírito Santo, Brazil. The family group consisted of adult male and female, three juvenile-subadult offspring, and an infant carried by the father. Two patterns of activity were identified: one in which two major feeding peaks were separated by a single long rest period and a relatively long travel distance between the two major feeding sites; and a second in which three major feeding peaks were separated by rest periods and travel was more evenly dispersed throughout the day.Callicebus personatus was similar toC. moloch in the folivorous supplementation of its frugivorous diet, and in having marked daily peaks in feeding and resting activities.C. personatus was similar toC. torquatus in the location of sleeping position on a large open bough, and the habit of calling from well within the territorial boundary. All three species are known to live in monogamous family units with parental care by the adult male, defend territories with loud intergroup vocalizations, and feed primarily upon a small number of widely dispersed fruits.     

Geophagy in masked titi monkeys (Callicebus personatus melanochir) in sBrazil

Geophagy was observed 14 times during an 11-month field study on the ecology and behavior of masked titi monkeys (Callicebus personatus melanochir). Geophagy took place in 12 cases on the surface of a leaf-cutting ant mound (Atta spec.). Analysis of chemical composition and natural features of the soils consumed by the monkeys showed elevated concentrations of several elements. In contrast, a lower concentration of carbohydrates was found in the ant mound sample compared to random non-ant mound soil samples. No difference in the concentration of clay elements, pH-value or percentage of organic matter was found between ant mound samples and randomly collected soil samples. Comparison of used versus not used samples failed to reveal significant clues about function of geophagy. However, chemical and physical properties of soils ingested support previous hypothesis that this behavior may aid in the adsorbtion of plant toxins.     

Communication in the Titi monkey, Callicebus

The communication system of Callicebus moloch includes a few olfactory and tactile signals, a moderate number of visual signals, and an enormous number of acoustic signals. The visual signal repertory is comparatively simple, and may be primitive in some respects. The acoustic signal repertory is very complex. It may illustrate the maximum elaboration which can beattained by species-specific language.     

Duetting in the Titi monkey Callicebus cupreus: structure,pair specificity and development of duets

Duets from a total of 6 female and 6 male titi monkeys (Callicebus cupreus) were analysed in order to provide an in-depth analysis of the duet structure, to investigate whether duets are pair specific and to examine whether duets of newly formed pairs differ from those of established pairs. Callicebus duets are composed of alternately uttered male and female contributions. Duets were pair specific as a result of a summation of individual attributes of the two mates rather than due to unidirectional or reciprocal song adaptation by mates. The two examined newly formed pairs produced species-typical duets from the first day on, but their duets showed greater variability in sequence durations than those of established pairs.     

Territorial shift in the yellow-handed titi monkey (Callicebus torquatus)

In this study, the ranging pattern of a single group of monogamous and territorial Callicebus torquatus was recorded over a 7-year period from 1974 to 1980. Data on ranging pattern were recorded by direct observation; daily movement patterns were plotted on an accurate, scaled map of the territory. Data were obtained during 1–3-month studies each year from 1974 to 1978 and in 1980, as well as during a 12-month study in 1979-1980. These studies show that the exclusive territory maintained by the group was not spatially stable over the 7-year period. The group gradually moved its territory to the northeast, to the extent that the territory used in 1980 was completely noncoincident with the territory used in 1974 by the same group. Analysis of the ranging pattern from the 12-month study indicates that the group did not exhibit seasonal preferences for different parts of its range. Seasonal ranging patterns, therefore, are not likely to account for the observed territorial shift. It is suggested that territorial shifting may be related to the need for monogamous groups to find new territories for their offspring.     

Genomic organization and chromosome mapping of the human homeobox gene HHEX.

In the present study, we report the genomic reconstruction of the human homeobox-containing gene HHEX by the use of the data available in public databases. This analysis allowed characterization of the gene organization showing that it is very similar to the mouse gene. Moreover the gene was mapped using FISH to 10q24.     

Genomic structure and chromosome mapping of human and mouse RAMP genes

The cDNAs for human and murine Receptor Activity Modifying Proteins and for the associated murine Calcitonin Receptor Like Receptor were isolated. The human RAMP1 and RAMP3 genes possess two introns and human RAMP2 possesses three introns. Human RAMP1 was assigned to chromosome 2q36-->q37.1, RAMP2 to 17q12-->q21.1 and RAMP3 to 7p13-->p12. Mouse Ramp1 was assigned to chromosome 1 and Ramp2 and Ramp3 were assigned to chromosome 11.     

Effects of Pair-Bond and Social Context on Male–Female Interactions in Captive Titi Monkeys (Callicebus moloch, Primates: Cebidae)

In monogamous species, an abiding relationship between a specific adult male and a specific adult female is a defining feature of the social system. The interactions between these individuals are influenced by many factors, including not only the history of their relationship (for example, development of a mutual bond), but also the immediate effects of the prevailing social context (for example, presence and sex of extra‐pair conspecifics). In this study we examined the effects of an existing bond and of social context on interactions between adult heterosexual pairs of the monogamous titi monkeys (Callicebus moloch). Twelve adult males and 12 adult females were tested with their cagemates and with an unfamiliar partner of the opposite sex in five social contexts: (1) mated male–female pair; (2) unfamiliar pair; (3) single female; (4) single male; and (5) empty stimulus cage. Results show that mated pairs were more affiliative than unfamiliar pairs and differentiated social contexts more sharply. Males were more responsive to context than females. Distance between mates was less and physical contact was more frequent in the presence of male–female pairs or a single male, than in the presence of a single female or an empty cage. These findings suggest that the presence and sex of strangers have a stronger influence on male–female interactions when the pair has an existing relationship.     

Extension of the Geographical Range of White-browed Titi Monkeys (<Emphasis Type=BoldItalic>Callicebus discolor</Emphasis>) and Evidence for Sympatry with San Martin Titi Monkeys (<Emphasis Type=BoldItalic>Callicebus oenanthe</Emphasis>)

White-browed titi monkeys (Callicebus discolor) have one of the largest distribution ranges of all titi monkey species, occurring from central Peru to southern Colombia. During a long-term study on the distribution of titi monkeys and other primates in Peru, we conducted extensive surveys in the San Martin Department of northeastern Peru. We encountered Callicebus discolor at the left bank of the Huallaga River, where the species most probably lives in sympatry with endemic San Martin titi monkeys (Callicebus oenanthe). Our study reveals an important extension of its formerly known distribution range. Massive deforestation activities in the region make studies on the habitat preferences of both species difficult, as most titi monkeys are confined to the remaining small remnants of the original forest. Urgent conservation measures are necessary to preserve the last lowland forests of San Martin.     

Genomic structure, chromosome mapping and expression analysis of the human AXIN2 gene

Conductin is a Wnt signalling protein and serves as a negative regulator of beta-catenin stability. We have previously isolated the human homolog (AXIN2) of the murine conductin gene and shown that it is mutated in colorectal cancer (CRC) with defective mismatch repair (MMR). Here we report the detailed genomic structure of this gene by analysis of cDNA and genomic clones. The gene spans > or =25 kb containing ten exons ranging from 96 bp to 904 bp. All splice donor and acceptor sites conform to the GT/AG rule. FISH (Fluorescence in situ Hybridization) analysis localized this gene to human chromosome band 17q24 and showed that it exists as a single copy in the human genome. Northern blot analysis from different human organs demonstrated that the AXIN2 gene is highly expressed in human thymus, prostate, testis, small intestine and ovarian tissues but expressed at a lower level in colon. The data reported here provides a framework for further analysis of this important Wnt signalling protein in vertebrate development and tumorigenesis.     

Effects of duration of separation on responses to mates and strangers in the monogamous titi monkey (Callicebus moloch)

Adult male and female titi monkeys form an intense social bond characterized by high levels of affiliative interactions between pairmates and agonistic responses to strangers. In natural settings, separation between mates can vary from brief periods, as when mates drift apart during feeding, to permanent separation, occasioned by desertion or death. In this study we asked how different durations of separation altered the behavior of male and female titi monkeys (Callicebus moloch). We compared the effects of brief separation such as might occur incidentally during feeding (1–2 h) with prolonged separation such as might occur if one partner died or deserted (5 days). Effects were observed during a 30 min reunion of pairmates or during a 30 min encounter with a stranger of the opposite sex. Following brief separation, interactions between mates and between strangers clearly differed in measures of affiliation, but not in behaviors indicative of arousal. Following prolonged separation, measures of arousal increased with both mated pairs and strangers. Females tended to interact more readily with a stranger following prolonged separation than after brief separation, but interactions between mates were essentially unchanged and differed substantially from those between strangers. The data suggest that the pair bond persists in titi monkeys after prolonged social isolation, despite increased interest in interacting with potential new partners. Am. J. Primatol. 43:225–237, 1997. © 1997 Wiley-Liss, Inc.     

The pairbond in the titi monkey (Callicebus moloch): intrinsic versus extrinsic contributions of the pairmates

Aspects of a monogamous relationship can be inferred by observing reactions of mated individuals to unfamiliar conspecifics. The present study examined the behaviours shown by male and female titi monkeys (Callicebus moloch) toward an opposite-sex stranger, and the effect of their pairmate's absence or presence on these encounters. Behaviours within unfamiliar heterosexual pairs showed superficial similarities to behaviours of mated pairs. Although there were few affiliative behaviours between unfamiliar individuals, animals were often in spatial proximity and even performed sexual behaviour. The visual presence of a pairmate clearly affected encounters between unfamiliar heterosexual pairs in several respects. The presence of a male pairmate had a much stronger influence on all behavioural measures compared to the presence of a female pairmate. Possible functional aspects of these results are discussed.     

Cloning and chromosome mapping of human and chicken Iroquois (IRX) genes.

Three highly homologous homeobox genes (caupolican, araucan and mirror) have been identified in Drosophila. These genes belong to the novel Iroquois complex, which acts as a pre-pattern molecule in Drosophila neurogenesis. Recently several vertebrate Iroquois homologues (Irx) were isolated and found to be involved in pattern formation of various tissues. Here we report cytogenetic mapping of four human and five chicken Iroquois genes by FISH. Our findings revealed that vertebrate Irx genes are clustered at two different loci.