Volumetric determination of metatarsal robusticity in a few living primates and in the foot ofOreopithecus

A new technique is described for the volumetric determination of metatarsal robusticity. Since volume was substituted for weight of a previously used technique, that technique is applicable to fossilized material. The comparability between the metric and volumetric techniques was tested and found to be sufficiently close to make the two techniques interchangeable. When the volumetric technique was applied to fourOreopithecus metatarsals, their robusticity was found to follow the 1→5 pattern (in which M5 is the least robust metatarsal), a pattern typical for all higher primates but present also inHomo. Their total robusticity was found to be closest toHomo and the gorilla, suggesting the likelihood of a terrestrial habitat forOreopithecus.     

The skeletal correlates of behavioral modification in the laboratory mouse (Mus musculus)

The effects of behavioral modification on the skeletal morphology of the laboratory mouse (Mus musculus) are investigated. Climibing, with increrased prehensile use of the foot, is found to bring about significant changes in metatarsal and long bone morphology. Differences in metatarsal robusticity related to weight-bearing differences associated with different locomotor patterns are reported for a natural history setting for Peromyscus.     

Hand use and metacarpal robusticity in Catarrhini

Recent studies,Rightmire (1972) andDay andScheuer (1973), have investigated the affinities of early hominid metacarpals from Swartkrans. Because of its extensive use in the analysis of metatarsals, the index of robusticity has also been applied to some fossil metacarpals. From the metatarsal analyses, it has been shown that within a group a variety of robusticity patterns exist with the average pattern occuring approximately 50 per cent of the time. This, coupled with the fact that it has also been shown that within the order Primates the pattern is not necessarily diagnostic of any locomotor category, has led us to investigate the usefulness of such an index in assessing primate metacarpals. In this study, metacarpal robusticity patterns and the Total Robusticity Quotient are established for seven cercopithecoid genera and the results correlated with hand use. It is found that although patterns of robusticity are not diagnostic of locomotor categories, the TRQ relates well to hand use: low TRQ's are found in primates which use their hands to walk on a flat substrate, while high TRQ's are diagnostic of arm swinging animals. Primates with reduced thumb use in a precision grip and little manipulative use of the hand have higher TRQ's than those with a good precision grip. The model derived from our sample of Cercopithecoidea is tested with a hominoid sample of four genera and found to be similarly applicable.     

Changes in metatarsal robusticity following experimental surgery

When a marginal metatarsal (M1 or M5) is amputated in neonatal rats, robusticity increases in all other metatarsals in both sexes. The robusticity increase is greatest in the metatarsal adjacent to the operation and declines in the direction away from it. The tripod structure of the rat's foot with its maximum robusticity of the marginal metatarsals is retained. When both marginal metatarsals are removed, this tripod arrangement is less clearly retained. When robusticity of all remaining metatarsals is averaged in a total robusticity quotient, total robusticity increase is greater in M1 than in M5 removal and greatest when both are removed. Total increase is greater in females than in males. Metatarsal robusticity increases result from retardation of longitudinal growth and increase of weight. The fact that some robusticity increases coincide with lesser length but not with increased weight suggests that in the process of robusticity increase longitudinal growth retardation precedes that of weight increase. Lesser length and greater weight of a long bone occurs also when hypofunction is produced in neonatal rats. However, in hypofunction the thickness of the compacta is increased leading to an obliteration of the medullary canal, while in the experimental metatarsals of this study, submitted to greater weight-bearing stresses, this canal is never reduced or obliterated.     

Implications of relative robusticity in the Olduvai metatarsus

The relative robusticity of the metatarsals in OH-8 is reviewed in light of the normal variation in metatarsal robusticity in Pan and Homo. The pattern in OH-8 is found to be fully commensurate with a striding gait.     

The Olduvai Hominid 8 foot: Adult or subadult?

Olduvai Hominid 8 (OH 8), an articulating set of fossil hominin tarsal and metatarsal bones, is critical to interpretations of the evolution of hominin pedal morphology and bipedal locomotion. It has been suggested that OH 8 may represent the foot of a subadult and may be associated with the OH 7 mandible, the type specimen of Homo habilis. This assertion is based on the presence of what may be unfused distal metatarsal epiphyses. Accurately assessing the skeletal maturity of the OH 8 foot is important for interpretations of the functional morphology and locomotor behavior of Plio-Pleistocene hominins. In this study, we compare metatarsal fusion patterns and internal bone morphology of the lateral metatarsals among subadult hominines (85 modern humans, 48 Pan, and 25 Gorilla) to assess the likelihood that OH 8 belonged to either an adult or subadult hominin. Our results suggest that if OH 8 is indeed from a subadult, then it displays a metatarsal developmental pattern that is unobserved in our comparative sample. In OH 8, the fully fused base of the first metatarsal and the presence of trabecular bone at the distal ends of the second and third metatarsal shafts make it highly improbable that it belonged to a subadult, let alone a subadult that matches the developmental age of the OH 7 mandible. In total, the results of this study suggest that the OH 8 foot most likely belonged to an adult hominin.     

Articular to diaphyseal proportions of human and great ape metatarsals

This study proposes a new way to use metatarsals to identify locomotor behavior of fossil hominins. Metatarsal head articular dimensions and diaphyseal strength in a sample of chimpanzees, gorillas, orangutans, and humans (n = 76) are used to explore the relationships of these parameters with different locomotor modes. Results show that ratios between metatarsal head articular proportions and diaphyseal strength of the hallucal and fifth metatarsal discriminate among extant great apes and humans based on their different locomotor modes. In particular, the hallucal and fifth metatarsal characteristics of humans are functionally related to the different ranges of motion and load patterns during stance phase in the forefoot of humans in bipedal locomotion. This method may be applicable to isolated fossil hominin metatarsals to provide new information relevant to debates regarding the evolution of human bipedal locomotion. The second to fourth metatarsals are not useful in distinguishing among hominoids. Further studies should concentrate on measuring other important qualitative and quantitative differences in the shape of the metatarsal head of hominoids that are not reflected in simple geometric reconstructions of the articulation, and gathering more forefoot kinematic data on great apes to better understand differences in range of motion and loading patterns of the metatarsals. Am J Phys Anthropol 143:198–207, 2010. © 2010 Wiley‐Liss, Inc.     

Serine esterases: structural conservation during animal evolution and variability in enzymic properties in the genus Drosophila

Both general esterases and acetylcholinesterases have been shown to be members of a homologous superfamily of serine esterases. A comparison of N-terminal sequences demonstrates that esterase-4 and-5 from Drosophila mojavensis belong to this family as well, with esterase-6 and esterase-P from D. melanogaster being the closest relatives. In order to investigate the presence of immunologically related esterases in other Drosophila species, crude larval extracts from five species were applied to two immunoaffinity columns with antibodies directed against esterase-4 and esterase-5 from D. mojavensis. The substrate preference for either 1- or 2-naphthyl acetate was determined. Both esterase-4 and esterase-5 from D. mojavensis are normally specific for 2-naphthyl esters, but at least three of the cross-reacting esterases from the other species have a preference for 1-naphthyl esters. This difference in substrate preference is another example of the variability observed with Drosophila esterases.     

News and Views

We surveyed the sleep‐wake patterns and lifestyle habits in a sample of Japanese first to third year junior high school children (n=638, age 12 to 15 yrs), of whom 29.3% were evening type, 64.1% intermediate type, and 6.6% morning type in preference. The morningness‐eveningness (M‐E) score was lower (more evening typed), 16.1 vs. 15.4 in first compared to third year students. There were significant gender differences, with girls showing a greater evening preference. Evening preference was associated with longer sleep latency, shortened sleep duration during schooldays and weekends, bad morning feeling, and episodes of daytime sleepiness. In contrast, morning preference was associated with higher sleep drive and better sleep‐wake parameters and lifestyle habits. Our results suggest the morning preference should be promoted among junior high school children to increase the likelihood of more regular sleep‐wake patterns and lifestyle habits.     

Morphine and cocaine increase serum‐ and glucocorticoid‐inducible kinase 1 activity in the ventral tegmental area

Drugs of abuse modulate the function and activity of the mesolimbic dopamine circuit. To identify novel mediators of drug‐induced neuroadaptations in the ventral tegmental area (VTA), we performed RNA sequencing analysis on VTA samples from mice administered repeated saline, morphine, or cocaine injections. One gene that was similarly up‐regulated by both drugs was serum‐ and glucocorticoid‐inducible kinase 1 (SGK1). SGK1 activity, as measured by phosphorylation of its substrate N‐myc downstream regulated gene (NDRG), was also increased robustly by chronic drug treatment. Increased NDRG phosphorylation was evident 1 but not 24 h after the last drug injection. SGK1 phosphorylation itself was similarly modulated. To determine the role of increased SGK1 activity on drug‐related behaviors, we over‐expressed constitutively active (CA) SGK1 in the VTA. SGK1‐CA expression reduced locomotor sensitization elicited by repeated cocaine, but surprisingly had the opposite effect and promoted locomotor sensitization to morphine, without affecting the initial locomotor responses to either drug. SGK1‐CA expression did not significantly affect morphine or cocaine conditioned place preference, although there was a trend toward increased conditioned place preference with both drugs. Further characterizing the role of this kinase in drug‐induced changes in VTA may lead to improved understanding of neuroadaptations critical to drug dependence and addiction.

     

The tarsal‐metatarsal complex of caviomorph rodents: Anatomy and functional‐adaptive analysis

Caviomorph rodents represent a major adaptive radiation of Neotropical mammals. They occupy a variety of ecological niches, which is also reflected in their wide array of locomotor behaviors. It is expected that this radiation would be mirrored by an equivalent disparity of tarsal‐metatarsal morphology. Here, the tarsal‐metatarsal complex of Erethizontidae, Cuniculidae, Dasyproctidae, Caviidae, Chinchillidae, Octodontidae, Ctenomyidae, and Echimyidae was examined, in order to evaluate its anatomical variation and functional‐adaptive relevance in relation to locomotor behaviors. A qualitative study in functional morphology and a geometric morphometric analysis were performed. We recognized two distinct tarsal‐metatarsal patterns that represent the extremes of anatomical variation in the foot. The first, typically present in arboreal species, is characterized by features that facilitate movements at different levels of the tarsal‐metatarsal complex. The second pattern, typically present in cursorial caviomorphs, has a set of features that act to stabilize the joints, improve the interlocking of the tarsal bones, and restrict movements to the parasagittal plane. The morphological disparity recognized in this study seems to result from specific locomotor adaptations to climb, dig, run, jump and swim, as well as phylogenetic effects within and among the groups studies.     

The cross-sectional geometry of the hand and foot bones of the hominoidea and its relationship to locomotor behavior

Cheiridia are valuable indicators of positional behavior, as they directly contact the substrate, but systematic comparison of the structural properties of both metacarpals and metatarsals has never been carried out. Differences in locomotor behavior among the great apes (knuckle-walking vs. quadrumanous climbing) can produce biomechanical differences that may be elucidated by the parallel study of cross-sectional characteristics of metacarpals and metatarsals. The aim of this work is to study the cross-sectional geometric properties of these bones and their correlation with locomotor behavior in large-bodied hominoids. The comparisons between bending moments of metacarpals and metatarsals of the same ray furnished interesting results. Metacarpals III and especially IV of the knuckle-walking African apes were relatively stronger than those of humans and orangutans, and metatarsal V of humans was relatively stronger than those of the great apes. Interestingly, the relative robusticity of the metacarpal IV of the quadrumanous orangutan was between that of the African apes and that of humans. The main conclusions of the study are: 1) cross-sectional dimensions of metacarpals and metatarsals are influenced by locomotor modes in great apes and humans; 2) interlimb comparisons of cross-sectional properties of metacarpals and metatarsals are good indicators of locomotor modes in great apes and humans; and 3) the results of this study are in accord with those of previous analyses of plantar pressure and morphofunctional traits of the same bones, and with behavioral studies. These results provide a data base from which it will be possible to compare the morphology of the fossils in order to gain insight into the locomotor repertoires of extinct taxa.     

Metatarsal robusticity in bipedal rats

All metatarsals have a significantly greater robusticity in the male than in the female rat. The robusticity formula of the rat's foot is 1 > 5 > 2 > 3 > 4. In bipedal rats that formula remains unchanged, but the robusticity of the metatarsals is increased especially in females. The tripod arrangement of the human foot with its particular robustness of the marginal metatarsals 1 and 5 and a strong calcaneum has been related to upright posture. The similar robusticity pattern in the rat's marginal metatarsals 1 and 5 raises the question of whether that part of the formula might not represent a more general plantigrade pattern.     

Swimmers,Diggers, Climbers and More,a Study of Integration Across the Mustelids’ Locomotor Apparatus (Carnivora: Mustelidae)

Phenotypic integration, defined as the coordinated co-variation of parts of an organism can be an important constraint on phenotypic diversification. Functional factors, by having an heterogeneous impact across the animal body, may reinforce the integration of some parts while causing a perturbation of the integration among other parts. The integration across the locomotor apparatus should thus reflect to a certain extent the locomotor ecology of the animal. Using the mustelids as study group, we track changes in the patterns of co-variation in species belonging to four different locomotor ecologies (terrestrial, semi-arboreal, semi-fossorial, and semi-aquatic). Our results highlight the strong overall integration in mustelid long bones. The main shape changes associated with co-variations between skeletal elements are the bone robustness and proportions of the epiphyses. The pattern of co-variation is, however, only slightly impacted by allometry. Changes in co-variation between species mostly scale with phylogenetic divergence time, except for the (Mustela putorius, M. eversmanni, M. lutreola) clade which, despite a short divergence time, presents strong differences in co-variation. Co-variation patterns differ between locomotor ecologies, but few of these variations match the hypothesis of a reduction of integration due to functional specialization. This may reflect our lack of knowledge on the functional modules in species with locomotor ecologies that differ from terrestrial locomotion rather than invalidate our a priori hypotheses.     

Stocking Density Affects Circadian Rhythms of Locomotor Activity in African Catfish,Clarias gariepinus

The effect of stocking density on the locomotor activity of African catfish C. gariepinus under different light regimes was investigated. C. gariepinus were stocked under different densities (1, 5, or 10 fish/tank), and their locomotor activity recorded under light-dark (LD), constant light (LL), constant darkness (DD), and LD-reversed (DL) regimens. Under the LD cycle, catfish showed a crepuscular activity pattern, irrespective of stocking density, with most of the daily activity concentrated around the light-onset and light-offset times. When fish were subjected to DD, all 4 tanks with medium (5 fish) and high (10 fish) stocking densities showed circadian rhythmicity, with an average period (τ) of 23.3?±?0.5 and 24.6?±?0.5?h, respectively. In contrast, only 2 low (1 fish) density tanks showed free-running rhythms. Under LL, activity levels decreased significantly in comparison with levels observed under LD and DD. Moreover, fish of 1, 2, and 3 out of the 4 tanks with low, medium, and high densities, respectively, showed free-running rhythms under these conditions. When the photocycle was reversed (DL), fish of 3, 2, and 4 out of the 4 tanks with low, medium, and high stocking densities, respectively, showed gradual resynchronization to the new phase, and transient cycles of activity were observed. These results suggest that stocking density of fish affected the display of circadian rhythmicity and the intensity of activity levels. Thus, fish kept in higher densities showed more robust rhythmicity and higher levels of daily activity, indicating that social interactions may have an influence on behavioral patterns in the African catfish. (Author correspondence: lmvera@um.es)     

Developmental changes in the activity and substrate specificities of mouse brain monoamine oxidase

Developmental changes in monoamine oxidase (MAO) activity in the mouse brain were investigated with the substrates -phenylethylamine (PEA), tryptamine, and 5-hydroxytryptamine (5-HT). In the newborn brain, MAO activity towards PEA was found to be much lower than the adult and to be inhibited by clorgyline in a double-sigmoidal fashion. The inhibition curve shifted to a single-sigmoidal pattern with age. MAO activity towards 5-HT as substrate was inhibited by 90% and in a single-sigmoidal manner by clorgyline throughout the postnatal life. Lineweaver-Burk plots with PEA as substrate presented two linear lines (apparentK _m: 28.6 and 4.1 M) for the newborn and one line (apparentK _m: 11.4 M) for the adult, respectively. The plot with highK _m value for the newborn brain disappeared in a clorgyline-treated preparation. These findings suggest that age-dependent alterations in the ratio of MAO-A/MAO-B activity affect the substrate specificity of the enzyme.     

Characterisation of a partially purified uracil phosphoribosyltransferase from the opportunistic pathogenCandida albicans

This paper describes for the first time the partial purification and properties of uracil phosphoribosyltransferase (UPRTase) from the yeastCandida albicans. UPRTase was purified 38 fold by acid precipitation, DEAE-Sephacel chromatography and ultrafiltration. Further purification of UPRTase was unsuccessful due to the labile nature of the enzyme and the failure in obtaining satisfactory stabilizing conditions. SDS-PAGE suggested that the enzyme exists as a dimer of two dissimilar subunits with molecular masses of 47 and 38 kDa. The pH optimum for phosphoribosylation was about 7.5 and the optimal Mg⁺⁺ concentration was 2 mM. The kinetics of the enzymes for its substrates, uracil and 5-phosphoribosyl-1-pyrophosphate (PRPP) were determined by measuring initial enzyme velocities over a wide range of concentrations of either substrate at different fixed concentrations of the second substrate. Graphic analysis of the data by Hanes-Woolf plots indicated that the reaction is indistinguishable from a double displacement reaction. Ping pong mechanism has been previously reported for other phosphoribosyltransferases. The enzyme has a low affinity for its substrates (K _m=70.5 and 186 µM for uracil and PRPP, respectively) as compared with those ofE. coli and baker's yeast. Inhibition studies indicate that 5-fluorouracil acts as an alternative substrate for UPRTase with 1.6 times higher specific activity.Abbreviations UPRTase Uracil phosphoribosyltranferase - PRTases phosphoribosyltransferases - PRPP 5-phosphoribosyl-1-pyrophosphate - 5-FC 5-fluorocytosine - 5-FU 5-fluorouracil - PEI polyethyleneimine - DTT dithiothreitol - DMSO dimethyl sulphoxide - PMSF phenylmethylsulphonyl fluoride - UMP uridine mono-phosphate     

Modification of the B-ring during flavonoid synthesis in Petunia hybrida: Introduction of the 3′-hydroxyl group regulated by the gene Ht1

The flower-color mutants of Petunia hybrida W37 and W18, which are homozygous recessive for the anthocyanin gene An3, accumulate flavanone glycosides in the flowers. It is concluded that the gene An3 is not directly involved in the synthesis of the C₁₅ skeleton, but that it probably takes part in modifying the skeleton. Complementation experiments with the mutants W18 and M5 show that the hydroxylating gene Ht1, which is reponsible for the introduction of the second hydroxyl group in the B-ring at position 3, is expressed after gene An3. In P. hybrida introduction of the 3-hydroxyl group is therefore not achieved by specific incorporation of caffeic acid during synthesis of the C₁₅ skeleton, but by hydroxylation of a C₁₅ skeleton. When anthocyanin synthesis is blocked by homozygous recessive hydroxylating genes Ht1 and Hf1, as in the mutant M5, dihydrokaempferol-7-glucoside is accumulated. This intermediate is discussed as a possible substrate for B-ring hydroxylation.     

Infection characteristics of a trematode in an estuarine isopod: influence of substratum

The estuarine isopod Cyathura carinata is a second intermediate host to microphallid trematodes, which use mud snails Hydrobia spp. and shorebirds as respectively first intermediate and final hosts. To identify processes responsible for infection patterns observed in C. carinata, a short-term microcosm experiment was conducted with both macroinvertebrates and one of their common parasites – Maritrema subdolum. Fine sand collected from two different shallow water sites was used to test if sediment type could affect infection rates. After 7 days at 25 °C, C. carinata from the substratum with the highest proportion of particles <125 m were more surface active and obtained significantly more M. subdolum individuals than isopods from the other sediment type. No parasite-induced effects on the hosts were found during this short-term experiment. The distribution pattern of microphallid cysts and mesocercariae inside the isopods revealed that M. subdolum cercariae primarily penetrated through the pleopods and afterwards located themselves in the middle-posterior region of the hosts body. Even if it was not possible to identify the factor responsible for the observed infection patterns (cercariae production and/or host behaviour), the results of this experiment indicate that small-scale factors, such as differences in substratum and associated features, may have considerable impact on infections of host populations.     

Purification,characterization and thermostability of lipase from a thermophilic Bacillus sp. J33

A thermostable lipase produced by a thermophilic Bacillus sp. J33 was purified to 175-fold with 15.6% recovery by ammonium sulphate and Phenyl Sepharose column chromatography. The enzyme is a monomeric protein having molecular weight of 45 kDa. It hydrolyzes triolein at all positions. The fatty acid specificity of lipase is broad with little preference for C12 and C4. The K_m and V_max for lipase with pNP-laurate as substrate was calculated to be 2.5 mM and 0.4 M min^-1 ml^-1 respectively. The immobilized enzyme was stable for 12 h at 60°C. Polyhydric alcohols such as ethylene glycol (2.5 M), sorbitol (2.5 M) and glycerol (2.5 M) were used as thermostabilizers. Lipase acquired a remarkable stability, since no deactivation occurred at 70°C for 150 min in the presence of additives.