Craniometrical variations among eastern Brazilian marmosets and their systematic relationships

The craniometrical variations among marmosets on the eastern coast of Brazil or theCallithrix jacchus group (C. jacchus, C. penicillata, C. kuhli, C. geoffroyi, C. flaviceps, andC. aurita) were analyzed to test various hypotheses for the arrangement of the species and phylogenetic relationships ofC. kuhli andC. flaviceps. Q-mode correlation coefficients and principal component analysis were employed to extract important shape factors from the craniometrical data. On this basis, the shape distances among the eastern Brazilian marmosets were found to be larger than those between the marmosets which are recognized as distinct species. This evidence supports the hypothesis that the members of theC. jacchus group are distinct species.C. kuhli shows the strongest resemblance toC. geoffroyi within theC. jacchus group.C. flaviceps is the most similar toC. aurita in its cranial shape. These findings indicate thatC. kuhli is most closely related toC. geoffroyi, whileC. flaviceps is toC. aurita.     

Protein variation,taxonomy and differentiation in five species of marmosets (genusCallithrix Erxleben, 1777)

The electrophoretic patterns of 15 protein systems codified for 20 genetic loci were investigated using horizontal electrophoresis. A total of 150 blood samples, from five species of the genusCallithrix were analyzed. Polymorphic variation was observed in 10 out 20 loci analyzed. The genotypic distributions are in Hardy-Weinberg equilibrium. The average heterozygosity (H) varied from 1% to 5%, similar to those observed for other Neotropical primates. The genetic distance coefficients revealed a phylogenetic separation of these species into two groups: (1) “argentata” (C. humeralifer andC. emiliae); (2) “jacchus” (C. jacchus, C. penicillata, andC. geoffroyi). This arrangement is according to the taxonomic arrangement proposed byHershkovitz (1977),de Vivo (1988), andMittermeier et al. (1988). The results in each group are compatible with the subspecies values recorded for the Platyrrhini. These values showed that:C. humeralifer andC. emiliae are subspecies ofC. argentata;C. jacchus, C. penicillata, andC. geoffroyi are subspecies ofC. jacchus. These results also suggest thatC. j. geoffroyi is the “jacchus” group taxon, most similar genetically to the “argentata” group.     

Mitochondrial pseudogenes and phyletic relationships ofCebuella andCallithrix (Platyrrhini, primates)

Two cytochromeb pseudogenes were isolated from PCR amplified products ofCebuella pygmaea DNA. These sequences showed insertions and deletions when compared to paralogous mitochondrial sequence regions of several primates. Phylogenetic analyses indicated that an ancestral pseudogene originated sometime before the divergence ofCebuella andCallithrix and that this sequence was later duplicated some 5.6 million years ago. Parsimony and distance analyses indicated thatCebuella pygmaea andCallithrix species of theargentata group were more closely related to one another than any of them was toCallithrix species of thejacchus group, in agreement with previous analyses based on nuclear genes and karyotypic data. These findings also indicated thatCallithrix is a paraphyletic genus, in agreement with previous propositions thatCebuella should be included within the genusCallithrix.     

Numerical analysis of the taxonomical status ofCallithrix kuhli based on measurements of the postcanine dentition

The postcanine dentition ofCallithrix geoffroyi, Callithrix penicillata, andCallithrix kuhli was compared metrically to determine whetherC. kuhli is a hybrid population ofC. geoffroyi andC. penicillata or not. Many measurements showed significant differences (p<0.01 orp<0.05) among the three marmosets. The dental variability inC. kuhli was not greater than those inC. geoffroyi andC. penicillata. Based on canonical analysis, the three marmosets are discriminated, andC. kuhli did not occupy a middle position betweenC. geoffroyi andC. penicillata on the first two canonical axes. In the projection of the first two principal components,C. penicillata tended to be distinguished fromC. geoffroyi andC. kuhli, andC. kuhli does not exhibit intermediacy betweenC. geoffroyi andC. penicillata. The present statistical analysis failed to provide evidence thatC. kuhli constitutes a population hybridized fromC. geoffroyi andC. penicillata, although the three marmosets were discriminated from each other. This may provide support for the hypothesis thatC. kuhli is not a hybrid population ofC. geoffroyi andC. penicillata but a distinct species.     

Chromosome Studies in Callitrichidae (Platyrrhini): A Comparison Between Callithrix and Leontopithecus

Chromosome studies in 20 Callithrix jacchus, 1 Callithrix flaviceps, and 1 Leontopithecus rosalia chrysomelas revealed evidence of chimerism in C. jacchus and L.r. chrysomelas, and the existence of a variant Y chromosome type in C. jacchus. Constitutive heterochromatin in C. jacchus was limited to the centromere region of the chromosome complement, and only in small amounts. A comparison between the G-band karyotypes of C. jacchus and L.r. chrysomelas showed clear similarities between species. Three structural rearrangements have probably occurred during phylogeny in the common ancestor from which these extant species later derived. The chromosome number of C. flaviceps was found to be 46.     

Proposed chromosomal phylogeny for the South American primates of the Callitrichidae family (Platyrrhini)

Cytogenetic and cytotaxonomic studies (G, C, sequential G/C, and NOR banding) were performed on 110 specimens representing the four genera of South American primates of the family Callitrichidae: Cebuella (C. pygmaea), Callithrix, groups argentata (C. argentata, C. emiliae, C. chrysoleuca, C. humeralifera, C. mauesi), and jacchus (C. aurita, C. geoffroyi, C. jacchus, C. kuhli, C. penicillata), Leontopithecus (L. chrysomelas, L. rosalia), and Saguinus (S. midas midas, S. m. niger). Mitotic chromosomes are characterized, and the rearrangements distinguishing the karyotypes of the taxa are inferred from arm homologies. The results were then converted into numerical data and submitted to cladistic analysis. The following conclusions were achieved: 1) Five karyotypic classes were observed, which correspond to the five taxa studied. Differences between them are as follows: a) Cebuella (2n = 44, 10 acrocentrics, A + 32 bi‐armed autosomes, bi) and the argentata group (2n = 44, 10A + 32bi) are different from each other due to a reciprocal translocation; b) both can be distinguished from the jacchus group (2n = 46, 14A + 30bi) by a centric fusion/fission rearrangement and a paracentric inversion; c) Leontopithecus (2n = 46, 14A + 30bi) and Saguinus (2n = 46, 14A + 30bi) differ from the jacchus group by a reciprocal translocation and three paracentric inversions; and d) Saguinus is different from the others by one paracentric inversion and pericentric inversions in at least four pairs of acrocentric autosomes. 2) The cladistic analysis separates Cebus (used as an outgroup) from the Callitrichidae groups, which forms a clade. Among the Callitrichidae, marmosets (Cebuella and Callithrix) form a sub‐clade, Cebuella and the argentata group being more closely related to each other than both are to the jacchus group. Tamarins (Leontopithecus and Saguinus) are also quite close, so that if one was not derived from the other, they with the marmosets share a common ancestor. Among the tamarins, Leontopithecus is karyotypically closest to the marmosets, specifically to the jacchus group. 3) Based on the chromosome information and considering the possible direction of the evolutionary changes (primitivity or phyletic dwarfism hypothesis, previously advanced by other authors), it was possible to propose the ancestral karyotypes and to develop two alternatives for the origin, differentiation and dispersion of the callitrichid. Both proposals are plausible, but when the geographical distribution is considered, the phyletic dwarfism hypothesis seems to be the most probable. Am. J. Primatol. 49:133–152, 1999. © 1999 Wiley‐Liss, Inc.     

Hybridization effects and genetic diversity of the common and black‐tufted marmoset (Callithrix jacchus and Callithrix penicillata) mitochondrial control region

Hybridization is continually documented in primates, but effects of natural and anthropogenic hybridization on biodiversity are still unclear and differentiating between these contexts remains challenging in regards to primate evolution and conservation. Here, we examine hybridization effects on the mitochondrial DNA (mtDNA) control region of Callithrix marmosets, which provide a unique glimpse into interspecific mating under distinct anthropogenic and natural conditions. DNA was sampled from 40 marmosets along a 50‐km transect from a previously uncharacterized hybrid zone in NE Brazil between the ranges of Callithrix jacchus and Callithrix penicillata. DNA was also collected from 46 marmosets along a 30‐km transect in a hybrid zone in Rio de Janeiro state, Brazil, where exotic marmosets appeared in the 1980s. Combining Callithrix DNA sampled inside and outside of these hybrid zones, phylogenetic and network analyses show C. jacchus and C. penicillata being parental species to sampled hybrids. We expand limited Callithrix population genetics work by describing mtDNA diversity and demographic history of these parental species. We show ancient population expansion in C. jacchus and historically constant population size in C. penicillata, with the latter being more genetically diverse than the former. The natural hybrid zone contained higher genetic diversity relative to the anthropogenic zone. While our data suggest hybrid swarm formation within the anthropogenic zone due to removed physical reproductive barriers, this pattern is not seen in the natural hybrid zone. These results suggest different genetic dynamics within natural and anthropogenic hybridization contexts that carry important implications for primate evolution and conservation. Am J Phys Anthropol 155:522–536, 2014. © 2014 Wiley Periodicals, Inc.     

A cladistic analysis of interspecific relationships ofSaguinus

The dental and cranial morphologies of all species ofSaguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess the interspecific relationships ofSaguinus.Saguinus are divided into two main groups; one consists ofS. oedipus, S. geoffroyi, andS. leucopus, and the other includesS. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas. In the former group,S. oedipus is more closely related toS. geoffroyi than either is toS. leucopus. In the latter group,S. labiatus, S. mystax, andS. imperator are classified into one group, andS. bicolor andS. midas form one monophyletic group.     

Systematics and evolution of the Jacchus group of marmosets (Platyrrhini)

Interspecific differentiation and geographic variation patterns in 39 skull traits of eastern Brazilian marmosets are analyzed. Eastern Callithrix taxa are distinct morphologically, and no evidence of intergradation among taxa is observed. Instead, there are sharp, stepped morphological boundaries among taxa, consistent with species‐level distinction. The morphological similarity cluster diagram obtained from Mahalanobis distances is different from available molecular trees, and the general picture emerging is that the eastern Callithrix taxa should be considered as good species arising recently in South American history. In particular, C. kuhlii is morphologically distinct from other marmoset taxa, including C. geoffroyi and C. penicillata, which were previously hypothesized to be the parental populations that formed C. kuhlii by hybridization. Furthermore, C. kuhlii populations from southeastern Bahia do not overlap morphologically with any C. penicillata population, including the upper São Francisco River populations that display skin colors and pelage patterns to some extent similar to true Kuhli's marmosets. There is a negative, though insignificant, correlation between the morphological distance matrix and a Mahalanobis distance matrix estimated from nine climatic variables, a pattern opposite to that expected under a parapatric speciation model. This result, together with the lack of clinal variation in skull traits, suggests that an allopatric model of speciation might best explain eastern marmoset diversification. Am J Phys Anthropol 2003. © 2002 Wiley‐Liss, Inc.     

Maternal care and infant development in <Emphasis Type="Italic">Callimico goeldii</Emphasis> and <Emphasis Type="Italic">Callithrix jacchus</Emphasis>

Callimico goeldii gives birth to single offspring, whereas other callitrichids, including Callithrix jacchus, twin. This study compares maternal effort and infant development in C. goeldii and C. jacchus; it is the first study to look at nursing frequency. Infants were observed from birth for 7 weeks in two captive groups each of C. goeldii and C. jacchus. C. goeldii mothers physiologically invested the same or less than C. jacchus mothers. C. goeldii mothers gained the same amount of weight during pregnancy in absolute terms as did the smaller C. jacchus. This results in a smaller gain in proportion to maternal weight but an equivalent proportional gain on a per fetus basis. C. goeldii mothers nursed their infants less based on duration of nursing bouts compared with C. jacchus mothers. C. goeldii mothers transported their infants exclusively through the first 2 weeks of life, which is longer than C. jacchus mothers, who exclusively transported infants only during the first week of life. As maternal infant carriage declined, other group members transported offspring in both species. C. goeldii infants engaged in independent locomotive sequences later in development and tasted solid foods less frequently than C. jacchus infants when compared at equivalent ages. A single, opportunistic milk sample obtained from a C. goeldii mother when her infant was 48 days old indicates that C. goeldii milk contains gross energy from crude protein within the range of variation observed in Callithrix milk. Despite the similarities in milk quality and prenatal effort in individual fetuses, C. goeldii infants gain weight faster from 0 to 18 months than do C. jacchus infants. A reduction in litter size allows C. goeldii mothers to spend more time carrying their infant and to delay weaning, thereby allowing accelerated infant and juvenile growth rates compared with C. jacchus.     

Update on the Phylogenetic Systematics of New World Monkeys: Further DNA Evidence for Placing the Pygmy Marmoset (Cebuella) within the Genus Callithrix

We determined DNA sequences spanning the 1.8-kb long intron 1 of the interstitial retinol-binding protein nuclear gene (IRBP) for Callithrix geoffroyi, Callithrix humeralifer, and Callithrix argentata. With the 22 previously determined IRBP intron 1 sequences—21 from the 16 currently recognized genera of New World monkeys—the enlarged IRBP data represent for the marmoset genus Callithrix both its argentata and its jacchus species groups. Maximum-parsimony and neighbor-joining trees, constructed for the 25 aligned IRBP intron 1 sequences, support a provisional phylogenetic classification with three families: Atelidae, containing subfamily Atelinae; Pitheciidae, containing subfamily Pitheciinae; and Cebidae, containing subfamilies Cebinae, Aotinae, and Callitrichinae. In order to have taxa at the same hierarchical rank at equivalent age, this classification has all living callitrichines in a single tribe, Callitrichini, with four subtribes: Saguinina (Saguinus), Callimiconina (Callimico), Leontopithecina (Leontopithecus), and Callitrichina (Callithrix with the pygmy marmoset, Cebuella pygmaea, merged into it). The DNA evidence shows not only that Callithrix must include C. pygmaea to be monophyletic but also that the times of separation of pygmaea and the argentata and jacchus species groups from one another are to be expected (<5 Ma—million years ago) for species in a single genus. On relating the time course of the ceboid radiation to biogeographic information, it appears that in mid-Miocene times (10–11 Ma) a basal callitrichin stock branched into the ancestral population of Saguinus in one clade and the ancestral population of Leontopithecus and Callimico–Callithrix (or Leontopithecus–Callimico and Callithrix) in another clade. The proto-lion tamarins migrated south and eastward, where they were isolated in refugia, becoming the genus Leontopithecus. The stock remaining in Amazonia gave rise to present-day Callimico and Callithrix. The latter genus occupied a vast geographic area, giving rise to the argentata and pygmaea groups in Amazonia and to the jacchus group in central and eastern Brazil.     

Intrinsic competition between the gregarious parasite,Cotesia glomeratus and the solitary parasite.Cotesia rubecula [Hymenoptera: Braconidae] for their host.Artogeia rapae [Lepidoptera: Pieridae]

The solitary endoparasite,Cotesia rubecula, was superior to the gregarious endoparasite,Cotesia glomeratus, in tests of intrinsic competition for their hostArtogeia rapae. When an egg ofC. rubecula was oviposited in the host prior to those ofC. glomeratus, C. rubecula always won the ensuing competition. When an egg ofC. rubecula was laid in the same host within 48 h after oviposition byC. glomeratus, C. rubecula was successful in more than 90% of the interactions. Even when the egg ofC. rubecula was oviposited in the same host 72 to 96 h after oviposition byC. glomeratus, C. rubecula won the competition approximately 33% of the time. The implications of intrinsic competition are discussed in relation to the establishment ofC. rubecula in an ecosystem containingA. rapae andC. glomeratus.      

Autecological investigations on marine diatoms. 4:Biddulphia aurita (Lyngb.) Brebisson et Godey—A succession of spring diatoms

Comparison of generation times ofBiddulphia aurita (Lyngb.) Brebisson and Godey with other diatoms indicated that the species can reach its best competitive position by growth from –1.5°C to about 6°C. The diatom demonstrates its optimum temperature at about 12°C. Yet, flowerings will occur at the lower temperatures only. Its presence in the early spring plankton is facilitated by its non-adhrence behaviour, that proved to be temperature dependent. At 0°C almost no adherence occurred, whereas at high temperaturesB. aurita adhered completely to the bottom of the glas vessels or pipettes. The importance ofB. aurita in the benthic community is discussed. The mutual differences in growth ofB. aurita, Chaetoceros debilis andThalassiosira nordenskioeldii resulted in a succession comparable with that found in nature.     

Chromosomal number and evolution in two Brazilian species of Callithrix

The Karyotypes of the Brazilian marmosets C. jacchus and C. penicillata are very similar. Both have 2n = 46. C. jacchus has one more metacentric pair and C. penicillata has one more submetacentric pair, whilc the sex chromosomes show distinet morphological differences.On the basis of the chomosome complement of these species some considerations about the process of chromosomal evolution are presented.A short comparative study of these and other species of the same genus shows that basic mechanisms such as centric fusion and pericentric inversions can explain the observed morphologic chromosomal variations.     

Comparative chromosomal study of five taxa of genus Callithrix,group Jacchus (Platyrrhini,primates)

The karyotypes of four marmoset species of the Callithrix jacchus group (C. aurita, C. kuhlii, C. geoffroyi, and C. penicillata) were investigated. The patterns of G-, C-, and NOR-bands of these karyotypes were compared with those of C. jacchus, previously described, in order to clarify the taxonomic relationships of this species group. All species present 2n = 46, 14 uni- and 30 biarmed autosomes, a median size submetacentric X chromosome, and the same NOR-band patterns. No rearrangement or constitutive heterochromatic variation differentiate these species, which differ only in the morphology of the Y chromosome. The data obtained indicate that, from the chromosomal point stand, the marmoset species of C. jacchus group constitute a homogeneous clade. Am J Primatol 41:53–60, 1997. © 1997 Wiley-Liss, Inc.     

Antagonistic interactions between fungal pathogens and phylloplane fungi of guava

Dominant phylloplane fungi of guava (Psidium guajava L.) were screened for their antagonistic activities against the two pathogens,Colletotrichum gloeosporioides andPestalotia psidii, bothin vitro andin vivo. Culture filtrates ofAspergillus niger, Fusarium oxysporum andPenicillium citrinum caused more than 50% growth inhibition ofC. gloeosporioides. Filtrates ofCephalosporium roseo-griseum andF. oxysporum were most effective in reducing the growth ofP. psidii. Volatiles produced from the cultures ofA. niger, F. oxysporum, P. citrinum andP. oxalicum inhibited the growth ofC. gloeosporioides, whereas volatiles fromC. roseo-griseum, F. oxysporum andTrichoderma harzianum inhibited the growth ofP. psidii. The inhibitory effect of volatiles decreased with increase in incubation time. In general, the maximum effect of volatiles was noticed after 48 h incubation. Different grades of colony interactions in dual cultures were recognised between the two pathogens and the phylloplane fungi examined. Maximum inhibition ofC. gloeosporioides was caused byAureobasidium pullulans, Cladosporium cladosporioides, epicoccum purpurascens, F. oxysporum andMyrothecium roridum, whereasAspergillus terreus, C. roseo-griseum andP. oxalicum significantly reduced the growth ofP. psidii. Application of a spore suspension of each test fungus inhibited lesion development of guava leaves caused by the test pathogensin vitro. Inhibition was more pronounced when the spore concentration was increased.A. pullulans, C. cladosporioides, E. purpurascens, F. oxysporum, andT. harzianum were found to be strongly antagonistic toC. gloeosporioides. A. niger, A. terreus, C. roseo-grisem andT. harzianum were strongly antagonistic toP. psidii.     

Synthesis of sterigmatocystin on a chemically defined medium by species ofAspergillus andChaetomium

Sterigmatocystin (ST) is a secondary metabolite and a principal mycotoxin known to be produced by over 30 species of filamentous fungi. It is also one of the late intermediates in aflatoxin biosynthesis. We have tested the ability of 7 species ofAspergillus, including 4 strains ofA. versicolor, one species ofBipolaris, and two species ofChaetomium, to produce ST on a sucrose-salts-phenylalanine defined medium as well as on three complex substrates. Highest ST production in our survey was by a strain ofA. versicolor grown on wheat, whereas, the highest ST production on defined medium was byC. cellulolyticum. To our knowledge, this is the first report of ST production byC. cellulolyticum on any substrate. In precursor feeding studies, resting cultures of wild typeA. nidulans andA. versicolor were unable to biotransform O-methylsterigmatocystin (OMST), the last known intermediate in aflatoxin biosynthesis. These results suggest that ST is the end product of polyketide metabolism in the strains tested.     

Fine structure of the dental enamel in the Family Callitrichidae (Ceboidea,primates)

The fine structure of the dental enamel was intensively examined in the Family Callitrichidae.Leontopithecus rosalia has the nonserial pattern, butCallimico goeldii andSaguinus midas appear more or less modified from the typical nonserial pattern asSaimiri sciureus has (see Figs. 1 & 5). On the other hand,Callithrix jacchus andCebuella pygmaea attain to the primitive stage of the multiserial pattern (see Figs. 4 & 6). So far as the structural patterns of the dental enamel are concerned, a serial trend is confirmed in the Callitrichidae; extending from the genusLeontopithecus through the generaCallimico andSaguinus to the generaCallithrix andCebuella. The genusSaguinus shows extremely wide interspecific variation in the fine structure of the dental enamel, ranging fromS. leucopus with the most primitive features toS. bicolor with the most advanced (see Figs. 2 & 3). The rows of enamel prisms are slightly twisted mesiodistally in the former species, but strongly folded in the latter. This reflects transitional stages from the nonserial pattern to the multiserial. As a whole, however, the genusSaguinus is still regarded as nonserial. Thus, there is a slight, but important gap between the genusSaguinus andCallithrix, as shown by the decussation of clusters (see Fig. 5), as well as by other characters.     

Interaction of Salivary alpha-Amylase and Amylase-Binding-Protein A (AbpA) of <Emphasis Type="Italic">Streptococcus gordonii</Emphasis> with Glucosyltransferase of <Emphasis Type="Italic">S. gordonii</Emphasis> and <Emphasis Type="Italic">Streptococcus mutans</Emphasis>

Background  

Glucosyltransferases (Gtfs), enzymes that produce extracellular glucans from dietary sucrose, contribute to dental plaque formation byStreptococcus gordoniiandStreptococcus mutans. The alpha-amylase-binding protein A (AbpA) ofS. gordonii, an early colonizing bacterium in dental plaque, interacts with salivary amylase and may influence dental plaque formation by this organism. We examined the interaction of amylase and recombinant AbpA (rAbpA), together with Gtfs ofS. gordoniiandS. mutans.