Studies on African saurian malarias: Plasmodium holaspi n. sp. from the flying lacertid Holaspis guentheri

The African flying lizard Holaspis guentheri (Lacertidae) from the Uluguru Mountains, Tanzania was found infected by an undescribed malarial parasite, Plasmodium holaspi n. sp. Gametocytes were elongate, approximately twice the size of host cell nuclei, and showed prominent, irregular pigment granules. Schizonts were oblong or formed as rosettes, approximated the host cell nucleus in size, and produced 8-18 merozoites. Maturing gametocytes contained large masses or blocks of chromatin which can obscure sexual differentiation by staining reaction, while young gametocytes and asexual stages almost always occupy marginal positions in host cells. These characteristics distinguish P. holaspi from all other saurian Plasmodium species. This is the first malarial parasite described from African lacertid species.     

基于线粒体细胞色素b基因序列探讨红喉姬鹟两亚种的分类地位

以线粒体DNA细胞色素b基因的全序列作为遗传标记 ,探讨红喉姬普通亚种 (Ficedulaparvaal bicilla)和指名亚种 (F .p .parva)的分类地位。应用Kimura 2 parameter法计算出红喉姬普通亚种个体间的遗传距离为 0 1%～ 0 2 % ,而与指名亚种之间的遗传距离为 6 4 % ,两亚种之间的遗传距离远远大于种间的遗传距离。结合形态学的特征我们认为 :红喉姬指名亚种和普通亚种应为两个独立种 ,分别为红喉姬 (F .albicilla)和红胸姬 (F .parva) ,两者的分化时间为 3 15～ 3 2 5百万年     

Eimeria cryptotis n. sp. (Apicomplexa: Eimeriidae) from the least shrew, Cryptotis parva (Insectivora: Soricidae), in north-central Texas

From March through November 1987, 14 least shrews, Cryptotis parva (Say), were collected in portions of north-central Texas and examined for coccidian parasites; only 1 (7.1%) was found to be passing oocysts. Eimeria cryptotis n. sp. is described herein as new and represents the only coccidian reported thus far from C. parva. Sporulated oocysts are subspherical, 16.4 x 15.3 (14-18 x 13-17) microns; shape index 1.1 (1.0-1.2) microns. A micropyle and oocyst residuum are absent, but a polar granule is present. The sporocysts are ovoid, 10.6 x 7.0 (9-11 x 6-8) microns; shape index 1.5 (1.4-1.8) microns. Stieda and substieda bodies and a sporocyst residuum are present. The sporozoites are elongate and only 2 could be observed well enough to measure (11.2 x 2.4 and 8.8 x 2.4 microns) because they are normally obscured by the sporocyst residuum. Sporozoites lack refractile bodies and contain a centrally located nucleus. The new species can be distinguished from the majority of insectivore coccidia on the basis of oocyst size.     

Diversity and evolution of the Mhc-DRB1 gene in the two endemic Iberian subspecies of Pyrenean chamois, Rupicapra pyrenaica

Major histocompatibility complex class II locus DRB variation was investigated by single-strand conformation polymorphism analysis and sequence analysis in the two subspecies of Pyrenean chamois (Rupicapra pyrenaica) endemic to the Iberian Peninsula. Low levels of genetic variation were detected in both subspecies, with seven different alleles in R. p. pyrenaica and only three in the R. p. parva. After applying the rarefaction method to cope with the differences in sample size, the low allele number of parva was highlighted. The low allelic repertoire of the R. p. parva subspecies is most likely the result of bottlenecks caused by hunting pressure and recent parasitic infections by sarcoptic mange. A phylogenetic analysis of both Pyrenean chamois and DRB alleles from 10 different caprinid species revealed that the chamois alleles form two monophyletic groups. In comparison with other Caprinae DRB sequences, the Rupicapra alleles displayed a species-specific clustering that reflects a large temporal divergence of the chamois from other caprinids, as well as a possible difference in the selective environment for these species.     

Morphological variation and sexual dimorphism of the cephalic scales in Lacerta bilineata

The Western green lizard (Lacerta bilineata) is a lacertid distributed throughout Mediterranean and Central Europe. Little is known about the morphological variability and sexual shape differences in this species. In this paper, the variation of the cephalic scales in L. bilineata is analysed by means of a geometric morphometric approach. A main structural pattern is characterized by negative allometry of the frontal and interparietal areas, and positive allometry of the parietal and frontoparietal scales. Sexual differences are described both in size and shape. In males, the scales are generally larger, with relative shortening of the frontal area, frontoparietal enlargement, occipital lengthening and bulging of the parietal scales, which compresses and narrows the interparietal and occipital areas midsagittally. This pattern is based on a shared allometric trajectory, with males displaying a peramorphic morphotype. However, males show some shape differences in the occipital area that are not size‐related, and cannot be interpreted in terms of general head enlargement. This structural trajectory can be related to the development of the skull, but the role of soft tissues (temporal, nuchal and masticatory muscles) must also be considered. The development of the jaw and nuchal muscles involved in intra‐ and intersexual behaviours could have played a pivotal role in the evolution of this pattern.     

The karyotype of Lacerta horváthi (Reptilia,Sauria, Lacertidae)

The chromosomes of Lacerta horváthi have been studied by means of conventional, C-banding, and silver-NOR techniques. The karyotype of this species, characterized by 36 acrocentric macrochromosomes, lacks the typical pair of microchromosomes shared by all other lacertid lizards. It is hypothesized that the microchromosomes could have been translocated to the large elements of the karyotype. The occurrence of such a rearrangement in the chromosome complement of L. horváthi underlines its isolation from the other species of the subgenus Archaeolacerta. The C-banding analysis evidences the existence of a female sex heteromorphism in which the W-chromosome has the same shape and size of the Z, but differs from it in being completely heterochromatic. The nucleolar organizer regions (NORs) are located on a pair of medium size chromosomes in subtelomeric position, where the standard Giemsa-staining reveals secondary constrictions.     

Group I introns within the nuclear-encoded small-subunit rRNA gene of three green algae.

Four group I introns from the nuclear-encoded (18S) rRNA genes of three chlorophycean green algae are described; two are in Dunaliella parva, and one each is in D. salina and Characium saccatum. The introns within the gene in the latter two organisms are located at the sites equivalent to the 5' and 3' introns of D. parva, respectively. All four introns lack open reading frames and are relatively small, 381-447 bp. Both primary- and secondary-structural features place these introns within subgroup IC1 described by Michel and Westhof. Phylogenetic relationships of the three intron-containing taxa and their relatives, as inferred from comparisons of 18S rDNA sequences, suggest that inheritance of the introns along with the gene can account for their present distribution. The discovery of these four introns, in addition to two others known to exist in other chlorophycean green algae, suggests that group I introns within the 18S rRNA gene may be relatively common in the green algae.     

麦穗鱼线粒体基因组序列测定及分析

利用麦穗鱼Pseudorasbora parva和相关鱼类的部分线粒体基因序列,设计出2对长批引物和30对短批引物,采用基于长PCR的2次PCR扩增法测定并注释麦穗鱼线粒体基因组全序列。结果表明,麦穗鱼线粒体基因组长16600bp,A+T含量为58.9%,37个基因位置及组成与其它硬骨鱼一致,均由13个蛋白编码基因、22个tRNA、2个rRNA基因和1个控制区(D-loop)组成。其中L链仅含8个tRNA(Pro、T yr、Ser、Ala、Asn、Cys、Glu、Gln)及ND6基因,其余基因皆由H链编码。基因排列紧密,间隔序列共计13处64bp,长度从1～32bp不等;基因重叠区7处23bp,重叠碱基数在1～7bp之间。13个蛋白编码基因中,除COI起始密码子为GTG外,其余均以ATG为起始密码子;有8个基因(ND1、ND2、COI、ATP6、ATP8、ND4L、ND5、ND6)3’端有完全的TAA或TAG终止密码子,其它5个基因终止密码子为不完整的TA(ND3和ND4)或T(COⅡ,COⅢ,Cyt b)。除tRNASer(AGY)外,其余21个tRNA基因的二级结构均为典型的三叶草结构。预测的lrRNA二级结构共有6个结构域,53个茎环结构,srRNA二级结构包含43个茎环结构。控制区(D-loop)存在3个结构区:终止序列区(TAS)、中央保守区(CSB-F、CSB-D)和保守序列区(CSB-1、CSB-2、CSB-3),其中TAS与DNA复制终止相关,出现茎环结构。     

Spauligodon aloisei n. sp. (Nematoda: Pharyngodonidae) parasite of Podarcis sicula (Reptilia: Lacertidae) from Italy

A new species of an oxyurid nematode is described from the large intestine of the lacertid lizard Podarcis sicula (Rafinesque. 1810) (Reptilia: Lacertidae) from Italy. Spauligodon aloisei n. sp. differs from other species of the genus by a combination of morphological and metrical characters, including a spined tail in males and females, absence of a spicule in males, arrangement of the last pair of the male caudal papillae, vulva location, and egg morphology. The species most similar to S. aloisei n. sp. is Spauligodon caspius Annayev, 1987, described from Tenuidactylus (=Gymnodactylus) caspius in Turkmenistan. Tail length and location of the excretory pore and vulvar opening separate S. caspius from S. aloisei n. sp. This article increases the number of species of this genus from reptiles in the Paleartic Realm to 19.     

New species of the genus Plesiolacerta (Squamata: Lacertidae) from the upper Oligocene (MP28) of Southern Germany and a revision of the type species Plesiolacerta lydekkeri

Abstract: The lacertid material from the locality of Herrlingen 8 (upper Oligocene, MP28) is described as a new species of the genus Plesiolacerta. The material is disarticulated and comprises isolated elements including parietal, frontal, maxilla and dentary. It can be assigned to a single species on the basis of the external surface ornamentation. This morphology is typical for the genus Plesiolacerta, but the material differs in detail from the type species P. lydekkeri. The most significant feature of the new species is that the occipital scute of the parietal bone is narrow, rectangular in shape and anteroposteriorly short. Hitherto, the last occurrence of this genus was in the lower Oligocene. This material represents the first evidence of the existence of this genus in the upper Oligocene. Therefore, our knowledge of its evolution is expanded by providing new data on its spatial and temporal ranges and morphology. This taxon has a much longer history than we thought. In addition, the Eocene species, P. lydekkeri, is reviewed here. P. lydekkeri shares the most lacertid synapomorphies and, given our present knowledge, Plesiolacerta is a taxon very close to or possibly within crown Lacertidae. The frontal and postorbitofrontal of Plesiolacerta are described for the first time. In view of the primitive morphology and early occurrence of Plesiolacerta, it seems that the feature of a longer anterior region of the frontal could be considered as a plesiomorphic feature within lacertid lizards, and the condition in Timon (approximately the same length) as derived.     

Molecular phylogenetic relationships of neotropical salamanders of the genus Pseudoeurycea

Pseudoeurycea, with 34 described species, is one of the most diversified groups of neotropical salamanders. I generated a phylogenetic hypothesis of relationships for Pseudoeurycea and related taxa, based on DNA sequences of 16S, Cyt b, and ND4 mitochondrial genes. The analyses include 27 species of Pseudoeurycea and samples from the monotypic Lineatriton, Ixalotriton, and Parvimolge. All phylogenetic analyses resulted in a paraphyletic Pseudoeurycea. Ixalotriton and Pseudoeurycea parva always form a monophyletic group. P. parva is transferred to Ixalotriton based on morphological and molecular grounds. The phylogenetic position of the newly defined Ixalotriton clade is uncertain since it is part of an unresolved basal polytomy. Parvimolge is closely related to Pseudoeurycea, and it is also part of the basal polytomy. Lineatriton, a highly specialized taxon, is deeply nested within Pseudoeurycea. In order to provide a taxonomic arrangement consistent with the monophyly of the different units that reflects both evolutionary history and morphological specialization, Pseudoeurycea should be split into several taxonomic units.     

Study of dentition in lizards from Gran Ganaria Island (Canary Islands) and its ecological and evolutionary significance

The dentition of Gallotia stehlini from one extant and two subfossil populations dated as 4000 and 2000 years before present was studied. Body measurements were similar in the two subfossil populations, but much greater than the largest sizes observed today in G. stehlini. The morphology of the dental cusps in this G. stehlini differs greatly from that of other Lacertidae, including other congeneric Canarian species; this has been connected with a vegetarian diet. A decrease in heterodonty with size of the animal is also seen which contrasts strongly with the models observed in the Mediterranean lacertid lizards.     

History and function of scale microornamentation in lacertid lizards

Differences in surface structure (ober-hautchen) of body scales of lacertid lizards involve cell size, shape and surface profile, presence or absence of fine pitting, form of cell margins, and the occurrence of longitudinal ridges and pustular projections. Phylogenetic information indicates that the primitive pattern involved narrow strap-shaped cells, with low posteriorly overlapping edges and relatively smooth surfaces. Deviations from this condition produce a more sculptured surface and have developed many times, although subsequent overt reversals are uncommon. Like variations in scale shape, different patterns of dorsal body microornamentation appear to confer different and conflicting performance advantages. The primitive pattern may reduce friction during locomotion and also enhances dirt shedding, especially in ground-dwelling forms from moist habitats. However, this smooth microornamentation generates shine that may compromise cryptic coloration, especially when scales are large. Many derived features show correlation with such large scales and appear to suppress shine. They occur most frequently in forms from dry habitats or forms that climb in vegetation away from the ground, situations where dirt adhesion is less of a problem. Microornamentation differences involving other parts of the body and other squamate groups tend to corroborate this functional interpretation. Microornamentation features can develop on lineages in different orders and appear to act additively in reducing shine. In some cases different combinations may be optimal solutions in particular environments, but lineage effects, such as limited reversibility and different developmental proclivities, may also be important in their genesis. The fine pits often found on cell surfaces are unconnected with shine reduction, as they are smaller than the wavelengths of most visible light.     

Salivary gland of the tick vector of East Coast fever. III. The ultrastructure of sporogony in Theileria parva

Sporogony of the sporozoan Theileria parva in the salivary gland of the tick vector of East Coast fever was studied in electron micrographs. The findings differ in several respects from previous interpretations based upon light microscopy. Cytokinesis of the primary sporoblast to form secondary and tertiary sporoblasts is not substantiated. Instead it is suggested that the parasite develops as a ramifying, multinucleate syncytium rapidly increasing in size and complexity until it gives rise to myriad sporozoites in a terminal episode of cytoplasmic fission. The proliferating nuclei initially occupy peripheral lobules that are continuous with a central labyrinth of branching and anastomosing processes which present a very large surface area for interchange of metabolites with the host cell cytoplasm. The membrane of the labyrinth is rich in cytostomes, but no evidence if found to bulk uptake of host cytoplasmic matrix or organelles into food vacuoles. Rhoptries are the first of the polar organelles of the parasite to develop and are associated with dense plaques irregularly distributed on the inner aspect of the parasite membrane. Micronemes form independently of the rhoptries at a later stage. After 3-4 days of tick feeding, sporogeny is complete and the infected salivary gland cell contains up to 50, 000 spherical or ovoid sporozoites about 1 micrometer in diameter. These are limited by a simple plasma membrane. The inner layer of the 'pellicle', the polar ring, and the conoid described for zoites of other Apicomplexa are lacking. Maturational changes are noted in sporozoites after sporogony is completed. Micronemes appear to increase in size, and possibly in number, from days 3-5 and the majority take up positions immediately subjacent to the plasmalemma.     

A Preliminary Electron Microscopic Study of East Coast Fever (Theileria parva Infection)

SYNOPSIS. The fine structure of various stages in the life cycle of Theileria parva is described. The appearance of the parasites suggests that there may be a double macroschizogony cycle. Micromerozoites are produced by a process of budding off from the body, known in light microscopy preparations as the residual body.     

DNA phylogeny, morphology and pathogenicity of Botryosphaeria species on grapevines

Several species of Botr yosphaeria are known to occur on grapevines, causing a wide range of disorders including bud mortality, dieback, brown wood streaking and bunch rot. In this study the 11 Botryosphaeria spp. associated with grapevines growing in various parts of the world, but primarily in South Africa, are distinguished based on morphology, DNA sequences (ITS-1, 5.8S, ITS-2 and EF1-α) and pathological data. Botryosphaeria australis, B. lutea, B. obtusa, B. parva, B. rhodina and a Diplodia sp. are confirmed from grapevines in South Africa, while Diplodia porosum, Fusicoccum viticlavatum and F. vitifusiforme are described as new. Although isolates of B. dothidea and B. stevensii are confirmed from grapevines in Portugal, neither of these species occurred in South Africa, nor were any isolates of B. ribis confirmed from grapevines. All grapevine isolates from Portugal, formerly presumed to be B. ribis, are identified as B. parva based on their EF1-α equence data. From artificial inoculations on grapevine shoots, we conclude that B. australis, B. parva, B. ribis and B. stevensii are more virulent than the other species studied. The Diplodia sp. collected from grapevine canes is morphologically similar but phylogenetically distinct from D. sarmentorum. Diplodia sarmentorum is confirmed as anamorph of Otthia spiraeae, the type species of the genus Otthia (Botryosphaeriaceae). A culture identified as O. spiraeae clustered within Botryosphaeria and thus is regarded as probable synonym. These findings confirm earlier suggestions that the generic concept of Botryosphaeria should be expanded to include genera with septate ascospores and Diplodia anamorphs.     

Relationship between diet and helminths in Gallotia caesaris (Sauria: Lacertidae)

Diet and helminth fauna were analysed in Gallotia caesaris, a small lacertid lizard endemic to El Hierro (Canary Islands, Spain) in order to study the evolutionary and functional relationships between the two traits. This species is omnivorous but consumed a high proportion (82.13%) of plant matter including not only seeds but also leaves and other vegetative parts. Helminth fauna included many helminth species typical of herbivorous reptiles. Both herbivory and helminth presence were higher than expected for a lizard of its size. Comparison with other lacertids suggests that both traits result from an adaptation to insular conditions but that some "evolutionary time" to develop them is needed. Canarian Gallotia lizards, a separate lineage evolving for a long time in insularity, constitutes the most advanced lacertid group in this way. Nevertheless, results for G. caesaris indicate that helminth fauna also changes seasonally tracking variation in diet (and herbivory) throughout the year, which suggests a dynamic interaction between diet and helminth parasites.     

An Alphoid-Like Satellite DNA Sequence Is Present in the Genome of a Lacertid Lizard

A PstI DNA family was isolated from the genome of a lacertid, Lacerta graeca. The 185-bp monomeric unit (pGPS) was cloned and hybridized to DNAs and chromosomes of several lacertid species. The data showed that pGPS hybridizes to the (1) centromeric or pericentromeric heterochromatin of almost all the chromosomes of L. graeca and (2) genomic DNA of species phylogenetically related and unrelated to L. graeca. The presence of pGPS even in species immunologically apart more than 30 million years suggests that this repeated family might be either very ancient or have been conserved during evolution due to its functional role. The latter hypothesis might be supported by the results of sequence analysis which showed some homology with both several alphoid sequences of primates and the CDEIII centromeric sequence of yeast. Segments of the satellite sequence are similar to the mammalian CENP-B box. These observations suggest that pGPS might have a role in determining the centromeric function in lacertid lizards. Received: 6 February 1997 / Accepted: 14 May 1997     

The Role of Lateral Blue Spots in Intrasexual Relationships Between Male Iberian Rock-Lizards, Lacerta monticola

Vertebrate males often show breeding colours that may function as reliable signals of status in intrasexual competition. In many lacertid lizards, males show a conspicuous row of small but distinctive blue spots that runs along their body side on the outer margin of the belly. However, no study has examined the role of these blue spots. We first analysed in a field population of the Iberian rock lizard, Lacerta monticola, the relationships between number of blue spots and some morphological traits, which are known to be related to males’ fighting ability. The number of spots seems to be an character showing ontogenetic change as large (generally older) males showed more blue spots than small (generally younger) males. Males with a higher body condition also showed a higher number of blue spots. Thus, a higher number of blue spots may be used to signal size, age or body condition. Many contiguous blue spots would result in a visual artefact consisting of a continuous blue band, which might be a reliable size‐ or condition‐dependent signal in some social contexts. We further examined in the laboratory whether male characteristics are related to dominance status. In males with similar body size or age, those with relatively larger heads were more dominant, whereas the number of blue spots was not important. Moreover, the number of blue spots in nature was not related to relative head size. Finally, we experimentally manipulated the presence and the number of blue spots of intruding males, and examined the aggressive response of resident males. Intruder individuals manipulated to cover all their blue spots received a lower amount of aggression. However, males with different numbers of manipulated blue spots received a similar number of aggressive responses. These results suggest that, during agonistic encounters, the presence of blue spots, but not their number, may elicit aggressiveness. Thus, blue spots may serve to identify an individual as an adult male, and to enhance body size of larger males.