Juvenile hormone-induced histone deacetylase 3 suppresses apoptosis to maintain larval midgut in the yellow fever mosquito.

SignificanceJuvenile hormone (JH), a sesquiterpenoid, regulates many aspects of insect development, including maintenance of the larval stage by preventing metamorphosis. In contrast, ecdysteroids promote metamorphosis by inducing the E93 transcription factor, which triggers apoptosis of larval cells and remodeling of the larval midgut. We discovered that JH suppresses precocious larval midgut-remodeling by inducing an epigenetic modifier, histone deacetylase 3 (HDAC3). JH-induced HDAC3 deacetylates the histone H4 localized at the promoters of proapoptotic genes, resulting in the suppression of these genes. This eventually prevents programmed cell death of midgut cells and midgut-remodeling during larval stages. These studies identified a previously unknown mechanism of JH action in blocking premature remodeling of the midgut during larval feeding stages.

Nuances of Whitefly Vector-Crinivirus Interactions Revealed in the Foregut Retention and Transmission of Lettuce Chlorosis Virus by Two Bemisia tabaci Cryptic Species.

Lettuce infectious yellows virus is the first crinivirus for which the retention of purified virions ingested into the whitefly (Bemisia tabaci New World (NW)) vector's foregut, has been demonstrated to be a requisite for successful virus transmission. This key finding supports the hypothesis that the determinant of foregut retention and transmission is present on the virion itself. However, whether this is also true for other criniviruses has not been established. Here, we provide evidence that lettuce chlorosis virus (LCV) acquired from plants is retained in the foreguts of both the B. tabaci NW and Middle East-Asia Minor 1 (MEAM1) vector species and transmitted upon inoculation feeding. An association between foregut retention and transmission by NW vectors is also observed following the acquisition and inoculation feeding of LCV virions purified using a standard procedure involving 2% or 4% (v/v) Triton™ X-100 (TX-100). However, while virions purified with 2% or 4% TX-100 are also retained in the foreguts of MEAM1 vectors, transmission is observed with the 4% TX-100-purified virions or when more vectors are used for acquisition and inoculation feeding. These results suggest that an intrinsic difference exists between NW and MEAM1 vectors in their interactions with, and transmission of, LCV virions.

Ontogeny and development of the gastrointestinal system in Indian walking catfish (Clarias magur) during its early development.

Ontogeny of the digestive tract and its accessory organs and their further development in the Indian walking catfish (Clarias magur) were examined in larvae, starting from the day of hatching until 35 days post-hatching (dph) reared at 28-29 °C. Many organs at their primordial stage were seen on the day of hatching. These include opened oral cavity with monolayered epithelial lining and very few newly emerging taste buds and goblet cells, primordial pharyngeal teeth on slightly stratified epithelia of the pharyngeal plate, stomach anlage with some degree of the mucosal fold, and a few newly forming gastric glands embedded under its mucosa, primordial anterior and posterior intestine with the smooth mucosal surface, anal opening, and primordial liver and pancreas. At 1 dph, the stomach appeared to be bilobed with the first evidence of food particle in it, and the intestine had some initial folding. On the day of hatching, goblet cells appeared in all lengths of the gut, but not densely, except in the stomach; on it, they appeared at 2 dph. Pancreatic zymogen granules also appeared on this day. Supranuclear vesicles first appeared on 4-5 dph (7.9 ± 0.5-8.6 ± 0.8 mm TL), and they continue to exist until 35 dph. The developmental sequence in this fish confirmed it as an altricial species with some major histomorphological events after the onset of feeding; these include-the appearance of fully developed-pharyngeal teeth at 4 dph and onwards, pyloric sphincter, anterior to posterior intestinal sphincter at 6 dph, and the continuous development of buccopharyngeal cavity and stomach in their shape, size, and functionality until the completion of metamorphosis. Overall, the information on gastrointestinal development in the early life stage of C. magur will be useful for understanding its larval digestive physiology, and this, in turn, will help in designing effective larval feed for growth and survival.

Functional foregut anatomy of the blue-green sharpshooter illustrated using a 3D model.

Sharpshooter leafhoppers (Hemiptera: Cicadellidae: Cicadellinae) are important vectors of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). This pathogen causes economically significant diseases in olive, citrus, and grapes on multiple continents. Bacterial acquisition and inoculation mechanisms are linked to X. fastidiosa biofilm formation and fluid dynamics in the functional foregut of sharpshooters, which together result in egestion (expulsion) of fluids likely carrying bacteria. One key X. fastidiosa vector is the blue-green sharpshooter, Graphocephala atropunctata (Signoret, 1854). Herein, a 3D model of the blue-green sharpshooter functional foregut is derived from a meta-analysis of published microscopy images. The model is used to illustrate preexisting and newly defined anatomical terminology that is relevant for investigating fluid dynamics in the functional foregut of sharpshooters. The vivid 3D illustrations herein and supplementary interactive 3D figures are suitable resources for multidisciplinary researchers who may be unfamiliar with insect anatomy. The 3D model can also be used in future fluid dynamic simulations to better understand acquisition, retention, and inoculation of X. fastidiosa. Improved understanding of these processes could lead to new targets for preventing diseases caused by X. fastidiosa.

Drosophila melanogaster sex peptide regulates mated female midgut morphology and physiology.

Drosophila melanogaster females experience a large shift in energy homeostasis after mating to compensate for nutrient investment in egg production. To cope with this change in metabolism, mated females undergo widespread physiological and behavioral changes, including increased food intake and altered digestive processes. The mechanisms by which the female digestive system responds to mating remain poorly characterized. Here, we demonstrate that the seminal fluid protein Sex Peptide (SP) is a key modulator of female post-mating midgut growth and gene expression. SP is both necessary and sufficient to trigger post-mating midgut growth in females under normal nutrient conditions, and likely acting via its receptor, Sex Peptide Receptor (SPR). Moreover, SP is responsible for almost the totality of midgut transcriptomic changes following mating, including up-regulation of protein and lipid metabolism genes and down-regulation of carbohydrate metabolism genes. These changes in metabolism may help supply the female with the nutrients required to sustain egg production. Thus, we report a role for SP in altering female physiology to enhance reproductive output: Namely, SP triggers the switch from virgin to mated midgut state.

Major differences in the larval anatomy of the digestive and excretory systems of three Oestridae species revealed by micro-CT.

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage, so they depend on an efficient assimilation and storage of nutrients during their parasitic larval stage. We describe the general morphology and provide volumetric data for the digestive and excretory organs of the three larval instars of the nasal bot fly Oestrus ovis L., using micro-computed tomography. The size of the digestive and excretory organs greatly increased across larval instars. In all instars, the two salivary glands were remarkably large and formed a 'glandular band' by coming together, but without lumina uniting, at their posterior ends. The distal region of the anterior Malpighian tubules was greatly enlarged and full of highly radio-opaque concretions. Moreover, the anatomy of O. ovis third-instar larva was compared to that of two species of, respectively, similar and different feeding habits: Cephenemyia stimulator (Clark) and Hypoderma actaeon Brauer. Whereas the general morphology and arrangement of the digestive and excretory systems of C. stimulator was similar to that of O. ovis, some differences were observed in H. actaeon: a swollen anterior region of the midgut, salivary glands shorter and not forming a 'band' and anterior Malpighian tubules narrowly uniform throughout their entire length.

Comparative Features of the Upper Alimentary Tract in the Domestic Fowl (Gallus gallus domesticus) and Kestrel (Falco tinnunculus): A Morphological, Histochemical, and Scanning Electron Microscopic Study.

The avian alimentary tract has evolved into different histologic structures to accommodate the physical and chemical features of several food types and flight requirements. We compared the esophagus, proventriculus, and gizzard of the domestic fowl, Gallus gallus domesticus (GGD) and kestrels, Falco tinnunculus (FT) using immunohistochemistry and scanning electron microscopy with various stains and lectins [Dolichos biflorus agglutinin (DBA) and Ricinus communis agglutinin I (RCA120)], and α-smooth muscle actin (α-SMA). The esophagus of GGD demonstrated thickened epithelium, muscularis mucosae, and inner circular longitudinal tunica muscularis layers; moderate outer longitudinal tunica muscularis layers; and a true crop. In contrast, the esophagus of FT showed a thin epithelium, no muscularis mucosae, moderate inner longitudinal and thick outer circular tunica muscularis layers, and no true crop. In the proventriculus, the nature of the secretion in GGD was neutral, but that of FT was acidic and neutral. In the gizzard, the muscle coat of GGD by α-SMA had no muscularis mucosae, unlike FT, which had muscularis mucosae. In summary, there are many histologic differences between GGD and FT to meet their different physiologic needs, such as feeding.

A postlarval instar of Phoxichilidium femoratum (Pycnogonida, Phoxichilidiidae) with an exceptional malformation.

Individuals of the marine chelicerate lineage Pycnogonida (sea spiders) show considerable regenerative capabilities after appendage injury or loss. In their natural habitats, especially the long legs of sea spiders are commonly lost and regenerated, as is evidenced by the frequent encounter of specimens with missing or miniature legs. In contrast to this, the collection of individuals with abnormally developed appendages or trunk regions is comparably rare. Here, we studied a remarkable malformation in a postlarval instar of the species Phoxichilidium femoratum (Rathke, 1799) and describe the external morphology and internal organization of the specimen using a combination of fluorescent histochemistry and scanning electron microscopy. The individual completely lacks the last trunk segment with leg pair 4 and the normally penultimate trunk segment bears only a single aberrant appendage resembling an extension of the anteroposterior body axis. Externally, the proximal units of the articulated appendage are unpaired, but further distally a bifurcation into two equally developed leg-like branches is found. Three-dimensional reconstruction of the musculature reveals components of two regular leg muscle sets in several of the proximal articles. This confirms interpretation of the entire appendage as a malformed leg and reveals an externally hidden paired organization along its entire proximodistal axis. To explain the origin of this unique malformation, early pioneering studies on the regenerative potential of pycnogonids are evaluated and (a) an injury-induced partial fusion of the developing limb buds of leg pair 3, as well as (b) irregular leg regeneration following near complete loss of trunk segments 3 and 4 are discussed. Which of the two hypotheses is more realistic remains to be tested by dedicated experimental approaches. These will have to rely on pycnogonid species with established laboratory husbandry in order to overcome the limitations of the few short-term regeneration studies performed to date.

Anatomy and histology of the alimentary canal of larvae and adults of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae).

The larvae of the lacewing Chrysoperla externa are important predators with the potential to be used in the biological control in agriculture. Although some studies provide important data on the gut morphology in lacewings, they are limited to few species. This study describes the anatomy and histology of the alimentary canal in the predatory larvae and herbivorous adult of C. externa. In larvae, the crop is the larger part of the foregut and it is connected to the midgut by the stomodeal valve. The midgut is an enlarged sac-like organ. At the mid-hindgut transition, there are eight Malpighian tubules. The hindgut is a non-functional vestigial region in the larvae. In adults, the crop has a diverticulum associated with large tracheal trunks, a conic proventriculus with sclerotized lips followed by an elongated tubular midgut. Histological analyses of larval and adult midgut show the presence of a single-layered epithelium with columnar cells with well-developed brush border, nests of regenerative cells, and a peritrophic matrix lining the midgut lumen. The hindgut in adults has an epithelium with cubic cells lined by a thin cuticular intima and rectal pads in the rectum. These data are discussed in comparison with the digestive tract in other Chrysopidae.

Anatomy of soft body of Pugilina cochlidium (Linnaeus, 1758) and P. erecta (Vermeij & Raben, 2009) (Neogastropoda: Melongenidae) from Thondi Coast-Palk Bay in Tamil Nadu, India / Anatomia do corpo mole de Pugilina cochlidium (Linnaeus, 1758) e P. erecta (Vermeij & Raben, 2009) (Neogastropoda: Melongenidae) de Thondi Coast-Palk Bay em Tamil Nadu, na Índia

The species of Pugilina cochlidium (Linnaeus, 1758) and P. erecta (Vermeij & Raben, 2009) has been studied in the present study. The female can be differentiated from the male by the absence of the cephalic penis and a complicated genital aparatus visible through the mantle skirt in both the sexes. In other aspects of the external features of female are quite to males. In both species the digestive system was similar with few differences in structure between each other. It consists of buccal mass, proboscis, salivary glands, accessory salivary glands, oesophagus, stomach, intestine, rectum and anus. The nervous system in both P. cochlidium and P. erecta is constituted by six ganglia which forms the circumoesophgeal ganglionic ring. Among the neogastropods there is a similarity in the organization of the reproductive systems. The female reproductive system is more complicated than that of male. The sexes are separated in these two species. The gross morphology of the reproductive system of P. cochlidium and P. erecta was almost similar. The present study aims to describe the digestive system, nervous system and reproductive system of two gastropods species P. cochlidium and P. erecta.

As espécies de Pugilina cochlidium (Linnaeus, 1758) e P. erecta (Vermeij & Raben, 2009) foram tomadas no presente estudo. A fêmea pode ser diferenciada do macho pela ausência do pênis cefálico e um complicado complexo genital visível através da saia do manto em ambos os sexos. Em outros aspectos das características externas da fêmea são bastante semelhantes aos dos machos. Em ambas as espécies, o sistema digestivo era semelhante, com poucas diferenças de estrutura entre si. Consiste em massa bucal, probóscide, glândulas salivares, glândulas salivares acessórias, esôfago, estômago, intestino, reto e ânus. O sistema nervoso em P. cochlidium e P. erecta é constituído por seis gânglios que formam um anel ganglionar circunoesofágico. Entre os neogastrópodes, há uma semelhança na organização dos sistemas reprodutivos. O sistema reprodutivo feminino é mais complicado que o masculino. Os sexos são separados nessas duas espécies. A morfologia macroscópica do sistema reprodutivo de P. cochlidium e P. erecta foi quase similar. O presente estudo tem como objetivo descrever o sistema digestivo, sistema nervoso e sistema reprodutivo de duas espécies, P. cochlidium e P. erecta.

Morphology of ctenostome bryozoans: 1. Arachnidium fibrosum.

The morphology of ctenostome bryozoans remains little investigated with only few species having been subject to more detailed studies. From all the seven main different superfamilies, only few representatives have been studied. The superfamily Arachnidioidea has particularly been neglected concerning detailed morphological and histological details. So far, not a single analysis specifically studied a representative of the family Arachnidiidae. Arachnidium-like forms have, however, often been regarded as potential cheilostome ancestors, the most successful group of bryozoans to date. The lack of any morphological data on this family called for a detailed investigation of one of its representatives. Hence, we analysed the general morphology and histology of Arachnidium fibrosum. Most striking morphological features previously unrecognized are a cardiac constrictor, previously almost unknown in the family, a single pair of apertural muscles consisting of proximal parieto-diaphragmatic and distal parieto-vestibular muscles, six pairs of duplicature bands, a lophophoral anus and retractor muscles attaching to the foregut. Although comparative data are limited, there seem to be two distinct different clades of arachnidiid ctenostomes that are characterized by their aperture and details of gut morphology. Further analysis of additional arachnidioidean species are required to confirm this.

Radula formation in two species of Conoidea (Gastropoda).

The radula is the basic feeding structure in gastropod molluscs and exhibits great morphological diversity that reflects the exceptional anatomical and ecological diversity occurring in these animals. This uniquely molluscan structure is formed in the blind end of the radular sac by specialized cells (membranoblasts and odontoblasts). Secretion type, and the number and shape of the odontoblasts that form each tooth characterize the mode of radula formation. These characteristics vary in different groups of gastropods. Elucidation of this diversity is key to identifying the main patterns of radula formation in Gastropoda. Of particular interest would be a phylogenetically closely related group that is characterized by high variability of the radula. One such group is the large monophyletic superfamily Conoidea, the radula of which is highly variable and may consist of the radular membrane with five teeth per row, or the radular membrane with only two or three teeth per row, or even just two harpoon-like teeth per row without a radular membrane. We studied the radulae of two species of Conoidea (Clavus maestratii Kilburn, Fedosov & Kantor, 2014 [Drilliidae] and, Lophiotoma acuta (Perry, 1811) [Turridae]) using light and electron microscopy. Based on these data and previous studies, we identify the general patterns of the radula formation for all Conoidea: the dorsolateral position of two groups of odontoblasts, uniform size, and shape of odontoblasts, folding of the radula in the radular sac regardless of the radula configuration. The morphology of the subradular epithelium is most likely adaptive to the radula type.

Anatomical and histological studies of the alimentary canal of adult maize leaf weevil, Tanymecusdilaticollis Gyllenhal, 1834 (Coleoptera: Curculionidae).

In this study, ananatomical and histological study was conducted on the alimentary canal of Tanymecusdilaticollis (Coleoptera: Curculionidae), which is an economic polyphagous pest species, to study the relationship between the structure of the alimentary canal and the feeding habit. Therefore, the structure of the alimentary canal of T. dilaticollis was examined using light and electron microscopies. Results have shown that the alimentary canal in T. dilaticollis is consisted of three separate regions as foregut, midgut, and hindgut structurally between the mouth and the anus, which pass from head, thorax, and abdomen. The foregut consists of pharynx, esophagus, crop and proventriculus and in the crop part, expansion is seen compared to other foregut parts. Midgut of T. dilaticollis is the largest part of digestion system. The anterior region of midgut is twofolds wider than the posterior region. The posterior midgut extends tubularly and it is connected to eightgastric caeca. The hindgut of T. dilaticollis consists of fourparts as pylorus, ileum, colon, and rectum. Well-developed muscle layers are found near the rectum and genital chamber. These results contribute to further studies on the ecology and biological control agents of Coleoptera and to provide a broad comparison of alimentary canal of Coleoptera species.

Anatomical and histological characterization of the digestive canal of the golden kingklip (Genypterus blacodes) / Caracterización anatómica e histológica del canal digestivo del congrio dorado (Genypterus blacodes)

Given the importance of the Golden kingklip (Genypterus blacodes) as an alternative to the production of salmonid species for worldwide diversification of aquaculture this study researched the morpho-histology of the digestive canal, providing a uniform nomenclature and basic information to support their nutritional management in captive conditions. The objective was to describe the normal morphology of the digestive canal. Twelve wild specimens were collected and dissected. Samples of the esophagus, stomach, liver, pyloric blind and intestines were obtained. An anatomical and histological description was performed. The digestive canal presented a short tubular esophagus, a slightly dilated, J-shaped stomach and thick walls. The stomach had a cardiac region that ended in a pyloric sphincter from which the intestine of thin walls. The intestine presented an anterior, middle and posterior segment. The anterior region of the first segment of the middle intestine presented 4-5 pairs of pyloric cecum. The middle intestine represented approximately 30 % of the total length of the digestive canal, with a smaller diameter compared to the first segment. The posterior intestine was separated from the middle intestine by a thick and powerful sphincter. The liver was large and elongated, and located in the peritoneal cavity located to the left plane and ventral to the swim bladder. The gallbladder was located lateral to the hepatic anterior wolf. The bile duct led to the duodenal region of the anterior intestine. Ventrally, the rectum ended in the anus, located in front of the anal fin. In general, the histological structures were variable according to the segment studied, a mucous tunic was recognized that presented a simple columnar epithelium, a lamina propria composed of loose connective tissue, a muscular layer of the mucosa composed of smooth muscle tissue and a submucosal layer composed of loose connective tissue, a circular and longitudinal stratum of muscular tunic, which had striated musculature and an adventitial tunic composed of a simple squamous epithelium. In conclusion, Golden kingklip (Genypterus blacodes) presents a digestive system typical of a carnivorous benthic fish adapted to feed on fish and crustaceans.

Dada la importancia del Congrio colorado (Genypterus blacodes) como alternativa a la producción de especies salmonídeas para la diversificación mundial de la acuicultura, el objetivo del presente estudio es describir la morfología normal del canal digestivo de esta especie, proporcionando una nomenclatura uniforme e información básica para apoyar su manejo nutricional en condiciones de cautiverio. Doce especímenes silvestres fueron colectados y disecados. Se obtuvo muestras del esófago, estómago, hígado, ciego pilórico e intestinos. Se realizó una descripción anatómica e histológica. El canal digestivo presentó un esófago tubular corto, un estómago ligeramente dilatado, con forma de J y paredes gruesas. El estómago presentaba una región cardíaca que terminaba en un esfínter pilórico desde el cual el intestino de paredes delgadas. El intestino presentaba un segmento anterior, medio y posterior. La región anterior del primer segmento del intestino medio presentó 4-5 pares de ciegos pilóricos. El intestino medio representó aproximadamente el 30 % de la longitud total del canal digestivo, con un diámetro menor en comparación con el primer segmento. El intestino posterior estaba separado del intestino medio por un esfínter grueso y poderoso. El hígado era grande y alargado, y ubicado en la cavidad peritoneal ubicado al plano izquierdo y ventral a la vejiga natatoria. La vesícula biliar se ubicó lateral al lobo anterior hepático. El ducto biliar desembocó en la región duodenal del intestino anterior. Ventralmente, el recto terminó en el ano, ubicado frente a la aleta anal. En general, las estructuras histológicas fueron variables según el segmento estudiado, se reconoció una túnica mucosa que presentaba un epitelio columnar simple, una lámina propia de la mucosa compuesta por tejido conectivo laxo, una capa muscular de la mucosa compuesta por músculo liso tejido y una capa submucosa compuesta de tejido conectivo laxo, un estrato circular y longitudinal de túnica muscular, que tenía musculatura estriada y una túnica adventicia compuesta por un epitelio plano simple. En conclusión, Congrio colorado (Genypterus blacodes) presenta un sistema digestivo típico de un pez bentónico carnívoro adaptado para alimentarse de peces y crustáceos.

External and digestive system morphology of the Tamandua tetradactyla.

Collared anteater is present throughout the Brazilian territory, but its morphology is little known. This study aimed to trace its external biometric profile and its digestive system. Six cadavers (4 ± 0.16 kg) from Paraíba, Brazil, were used. The thoracic limbs were more robust when compared to pelvic. The length of the tail is below that described in specimens from south-eastern Brazil, probably due to the greater use of the tail suspension function in the leafier forests in this region. The tongue had no papillae and had keratinized squamous epithelium. The oesophagus was tubular with keratinized squamous epithelium. The stomach was single-chambered with simple prismatic epithelium and presence of tubular glands in the lamina propria. The pyloric region was thicker and had larger folds of mucosa; the greater curvature was approximately three times greater than the smaller. The small intestine was larger than that found in other Xernathra species such as sloth, an herbivore animal; in the large intestine, the caecum was small. The colon was subdivided ascending, transverse and descending, with simple prismatic epithelium. This study is the first to bring the description of the external and digestive system morphometrics of collared anteater adult and pup. The anatomical characteristics of the digestive system show that the digestion of the anteaters, although not using the fermentation, is not as rapid as in other Xenarthras, probably due to the material of the exoskeleton of the insects by them consumed. The data generate subsidies for the clinic, surgery, preservation and nutrition of this species.

Phylogenetic analysis of phenotypic characters of Tunicata supports basal Appendicularia and monophyletic Ascidiacea.

With approximately 3000 marine species, Tunicata represents the most disparate subtaxon of Chordata. Molecular phylogenetic studies support Tunicata as sister taxon to Craniota, rendering it pivotal to understanding craniate evolution. Although successively more molecular data have become available to resolve internal tunicate phylogenetic relationships, phenotypic data have not been utilized consistently. Herein these shortcomings are addressed by cladistically analyzing 117 phenotypic characters for 49 tunicate species comprising all higher tunicate taxa, and five craniate and cephalochordate outgroup species. In addition, a combined analysis of the phenotypic characters with 18S rDNA-sequence data is performed in 32 OTUs. The analysis of the combined data is congruent with published molecular analyses. Successively up-weighting phenotypic characters indicates that phenotypic data contribute disproportionally more to the resulting phylogenetic hypothesis. The strict consensus tree from the analysis of the phenotypic characters as well as the single most parsimonious tree found in the analysis of the combined dataset recover monophyletic Appendicularia as sister taxon to the remaining tunicate taxa. Thus, both datasets support the hypothesis that the last common ancestor of Tunicata was free-living and that ascidian sessility is a derived trait within Tunicata. "Thaliacea" is found to be paraphyletic with Pyrosomatida as sister taxon to monophyletic Ascidiacea and the relationship between Doliolida and Salpida is unresolved in the analysis of morphological characters; however, the analysis of the combined data reconstructs Thaliacea as monophyletic nested within paraphyletic "Ascidiacea". Therefore, both datasets differ in the interpretation of the evolution of the complex holoplanktonic life history of thaliacean taxa. According to the phenotypic data, this evolution occurred in the plankton, whereas from the combined dataset a secondary transition into the plankton from a sessile ascidian is inferred. Besides these major differences, both analyses are in accord on many phylogenetic groupings, although both phylogenetic reconstructions invoke a high degree of homoplasy. In conclusion, this study represents the first serious attempt to utilize the potential phylogenetic information present in phenotypic characters to elucidate the inter-relationships of this diverse marine taxon in a consistent cladistic framework.

Colobine forestomach anatomy and diet.

Colobine monkeys have complex, multichambered, foregut-fermenting stomachs with either three ("tripartite") or four ("quadripartite," adding the praesaccus) chambers where a commensal microbiome digests plant cell walls and possibly detoxifies defensive plant chemicals. Although different potential functions for the praesaccus have been suggested, little evidence exists to support any of the proposed functions. To address the issue of the function of the praesaccus, we collated literature data on diet and compared tripartite and quadripartite species. Our results suggest that the praesaccus is an adaptation to a dietary niche with a particularly high reliance on leaves as fallback foods in colobine clades with quadripartite stomachs, and a higher reliance on fruits/seeds as foods at times of high fruit availability in clades with tripartite stomachs. This supports the notion that a large gut capacity is an important characteristic by which folivores survive on a high fiber diet, and that this large gut capacity may not be necessary for some species if there are seasonal peaks in fruit availability.

Microanatomy of the American Malaria Vector Anopheles aquasalis (Diptera: Culicidae: Anophelinae) Midgut: Ultrastructural and Histochemical Observations.

The mosquito gut is divided into foregut, midgut, and hindgut. The midgut functions in storage and digestion of the bloodmeal. This study used light, scanning (SEM), and transmission (TEM) electron microscopy to analyze in detail the microanatomy and morphology of the midgut of nonblood-fed Anopheles aquasalis females. The midgut epithelium is a monolayer of columnar epithelial cells that is composed of two populations: microvillar epithelial cells and basal cells. The microvillar epithelial cells can be further subdivided into light and dark cells, based on their affinities to toluidine blue and their electron density. FITC-labeling of the anterior midgut and posterior midgut with lectins resulted in different fluorescence intensities, indicating differences in carbohydrate residues. SEM revealed a complex muscle network composed of circular and longitudinal fibers that surround the entire midgut. In summary, the use of a diverse set of morphological methods revealed the general microanatomy of the midgut and associated tissues of An. aquasalis, which is a major vector of Plasmodium spp. (Haemosporida: Plasmodiidae) in America.

Functional cytology of the hepatopancreas of decapod crustaceans.

This article reviews the morphogenesis, morphology, histology, ultrastructure, and structural-functional relationships of the hepatopancreas, the main metabolic organ of the Decapoda. The hepatopancreas develops in early larval stages from a pair of lateral lobes of the midgut anlage. In adults, it consists of hundreds of blindly ending tubules that are enveloped by a muscle net consisting of longitudinal and circular fibers. Stem cells at the distal ends of the tubules give rise to three ultrastructurally different epithelial cell types, the R-, F-, and B-cells. Histochemistry, immunohistochemistry, in situ hybridization, and monitoring of ultrastructural changes under different experimental conditions allowed the attribution of functions to these cell types. R-cells serve for the absorption and metabolization of nutrients, storage of energy reserves and minerals, synthesis of lipoproteins for export to other organs, detoxification of heavy metals, and excretion of uric acid. F-cells synthesize digestive enzymes and blood proteins involved in oxygen transport and immune defense. They also detoxify some heavy metals and probably organic xenobiotics. B-cells are assumed to produce and recycle fat emulsifiers. The hepatopancreas tubules lack nerves. The presence of scattered M-cells with putative endocrine function in the epithelium suggests that the hepatopancreas is mainly hormonally controlled. M-cells probably represent a self-perpetuating cell lineage independent from E-cells. The interstitium between the tubules contains connective tissue, arterioles, hemolymph with circulating hemocytes, and fixed phagocytes that eliminate pathogens. The hepatopancreas is histologically and ultrastructurally uniform throughout the Decapoda, despite their broad variety in body size, morphology, life style, and ecology. However, in a few cavernicolous and deep-sea shrimps parts of the hepatopancreas are transformed into large oil storing and bioluminescent compartments. Within the malacostracan crustaceans, the hepatopancreas of the Decapoda is most similar to the digestive gland of the Euphausiacea, supporting close taxonomic relationship of these two taxa.