Spine Length Research Articles

Morphology and Phylogeny of Scrippsiella precaria Montresor & Zingone (Thoracosphaerales, Dinophyceae) from Korean Coastal Waters

The dinoflagellate genus Scrippsiella is a common member of phytoplankton and their cysts are also frequently reported in coastal sediments worldwide. However, the diversity of Scrippsiella in Korean waters has not been fully investigated. Here, several isolates of Scrippsiella precaria collected from Korean waters and germinated from resting cysts were examined using light and scanning electron microscopy. The resting cysts were characterized by pointed calcareous spines and one or two red accumulation bodies, and the archeopyle was mesoepicystal, representing the loss of 2–4′ and 1–3a paraplates. Rounded resting cysts were found in culture, and an increase in spine length was observed until 8 days of development. Korean isolates of S. precaria had the plate formula of Po, X, 4′, 3a, 7″, 6C, 4S, 5‴, 2⁗. There were differences in the cell size and location of the red body between Korean isolates and previously described cells of S. precaria. In addition, the Korean isolates of S. precaria had two types of the 5″ plate that either contacted the 2a plate or not. Molecular phylogeny based on internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences revealed that the Korean isolates were nested within the subclade of PRE (S. precaria and related species) in the clade of Scrippsiella sensu lato, and that the PRE subclade had two ribotypes: ribotype 1 consisting of the isolates from Korea, China, and Australia, and ribotype 2 consisting of the isolates from Italy and Greece. Lineages between isolates of ribotype 1 were likely to be related to the dispersal by ocean currents and ballast waters from international shipping, and the two types of spine shapes and locations of the 5″ plates may be a distinct feature for ribotype 1.

Alternative tactics in male African ground squirrels: the impact of variable rainfall on condition and physiology

Abstract Alternative reproductive tactics occur when conspecifics of the same sex use different behavioral processes to maximize reproductive success. Resource availability can have significant impacts on the proximate factors impacting the success and persistence of alternative tactics, such as an individual’s physiology, immunity, and body condition. Male Cape ground squirrels (Xerus inauris) display two alternative tactics, with some mature males dispersing from their natal groups and joining bands of nonrelated males (band males), whereas others do not disperse and remain philopatric in their natal groups past sexual maturation (natal males). Despite differences in metabolism, home ranges, and behavior, there is no difference in reproductive success between the two tactics, allowing us to test if rainfall (as a measure of primary productivity) influences body condition and physiological indices in tactics when fitness is equal. Over a period of 6 years, rainfall was positively related to body condition (mass–spine length residuals) in band males (N = 76), but not in natal males (N = 75). When we followed 18 males prior to and after dispersal, we also found a positive relationship between body condition and age following dispersal, but not prior to dispersal, and natal males maintained a better body condition in low rainfall years. During 2 years of low rainfall, band males (N = 39) had higher total ectoparasite abundance, and white blood cell differentials, implying they are less able to tolerate parasitic infection than natal males (N = 31). We found no difference in bacterial growth inhibition between tactics, suggesting that band and natal males both are equally resistant to parasites. The poorer body condition of band males during lower rainfall suggests they are less tolerant to parasites in these years. Dispersal during years of low rainfall thus may increase the costs to body condition and parasite infection, but the reproductive benefit of overlapping with more females may contribute to maintaining equal fitness between tactics.

ВЗАИМОСВЯЗЬ ПАРАМЕТРОВ ГРУДНОЙ КЛЕТКИ С МОРФОМЕТРИЕЙ ТЕЛА И ВНУТРЕННИХ ОРГАНОВ У САМОК НОРОК ХЕДЛУНД (h/h), ПАСТЕЛЬ (b/b), СКАНБЛЕК (N/N, N/n)

The study of morphometric features of the body and the establishment of relationships between them is the basis for the selection of American minks (Neovison vison). In this regard,the study of body parameters and identifying correlations with significant selection indicators are of practical importance. At the same time, such a morphological indicator as chest girth has not practically been studied. After examining the carcasses (after skinning) of female Hedlund minks (h/h), Pastel (b/b), Scanblack (N/N, N/n) (20 animals of each genotype) slaughtered at the age of 7.5 months, the researchers found that their average weight does not have significant differences and ranges from 834.0±21.85 to 891.3±13.33 g. At the same time, the body length of Pastel minks is 40.4±0.38 cm, which is reliably 1.2 cm larger than Headlund and Scanblack. The girth of the chest behind the shoulder blades (OGZL) has significant differences and is 13.5±0.17 cm for Headlunds, 14.7±0.13 cm for Pastels, and 14.2±0.21 cm for Scanblack, as well as chest girth along the last rib (OGPR) which is 17.5±0.16 cm, 19.7±0.20 cm and 18.6±0.29 cm, respectively. According to the formula: Krgk = (OGZL + (OGPR-OGZL) / DG × 10) / OGZL, where DG is the length of the thoracic spine, we found that this indicator does not have significant breed differences and is within 1.21±0.01–1.23±0.01. At the same time, Krgk negatively correlates with body weight and length. In females of all studied genotypes, Krgk was in the range from 1.15 to 1.31, while the more significant the coefficient value, the more pronounced the “triangle” of body expansion. Thus, the researchers deduced the following correspondences – females whose Krgk value is close to 1.15–1.19 belong to the coarse type of constitution, females with intermediate values 1.21–1.24 – to the strong type, accordingly, and 1.27–1.31 – to tender

Experimental Study of Population Variations on the Morphology and Reproduction of <i>Daphnia galeata</i> from Three Chinese Lakes

Environmental heterogeneity affected the genetic differentiation and phenotypic plasticity of Daphnia spp. populations in different lakes. However, the effect mechanism of lake population on the morphology and reproduction of Daphnia spp. was still unclear. This paper studied the differences of the morphology and reproduction of D. galeata populations from three Chinese lakes (CH: Lake Chaohu, NH: Lake Nanhu, EH: Lake Erhai), which the area size, nutrient levels, phytoplankton biomass and dominant fish were obviously various in the three lakes. The results showed that lake population affected significantly the morphology (helmet length and tail spine length) and reproduction (no. offspring at first reproduction per female-1) of D. galeata. Both helmet lengths and tail spine lengths of three D. galeata populations increased quickly within the first five instars, and afterwards showed various patterns. Multiple comparisons indicated that helmet lengths of NH population were significantly higher than those in EH and CH populations (P<0.001) whereas tail spine lengths of NH population were significantly smaller than those in EH (P=0.001) and CH (P=0.003) populations. The ratio of relative helmet length of CH population was significantly shorter than those of EH population (P<0.001) and NH population (P<0.001), and the ratio of relative tail spine length at first pregnancy of EH population was significantly longer than those of CH population (P<0.001) and NH population (P<0.001). Moreover, there is four juvenile instars in EH population whereas there are three juvenile instars in CH and NH populations. With the increase of adult instars, the number of offspring produced by D. galeata in all three populations displayed a similar pattern, which increased quickly at first, and then gradually decreased. Average maximum number of offspring at first reproduction (6.3±1.4 ind. per female-1) appeared in CH population, followed by EH (5.2±1.7 ind. per female-1) and NH (4.9±1.4 ind.•per female-1) populations. The innate rate of increase of CH population was relatively higher than those of EH and NH populations, but no significant differences among three populations were observed. Our results suggested that environmental heterogeneity could affect the reproduction and morphological plasticity of Daphnia spp. in different lakes.

Signatures of natural selection in morphological quantitative traits in Argentinean populations of Senegalia gilliesii (Fabaceae).

In order to elucidate the role of evolutionary forces in shaping the variation of quantitative traits in Senegalia gilliesii we evaluate seven phenotypic traits in three Argentinean populations, two of them sharing environmental and vegetation type conditions, and a third one ecologically differentiated from the former. The phenotypic traits were compared with molecular markers. Here, we search for signatures of selection by means of the comparison PST-FST . We assessed if the averages of the seven phenotypic traits were different among populations by means of ANOVA and we performed discriminant analysis of principal components (DAPC) for both morphological and molecular data. The ANOVA showed significant results only for two traits. For all foliar traits and two spine traits, the PST-FST comparison suggested the occurrence of stabilizing selection. The DAPC obtained from AFLP data showed three well defined groups of populations; when the same analysis was conducted with morphological data the scatterplot showed high overlapping among individuals and could not separate the populations. Overall, our findings suggest a prominent role of stabilizing selection in all foliar traits and stipular spine length. These results could be extrapolated to other tropical and subtropical acacias. Further studies are needed to analyse the mechanisms underlying genetic differentiation in natural populations of S. gilliesii, find its relationship with eco-geographical variables.

A new species of the cardinalfish genus Apogon (Teleostei, Apogonidae) from the southern Red Sea and Indian Ocean with comments on phylogenetic relationships within the Apogonini.

Apogon fugax is described as a new species of cardinalfishes based on a specimen trawled off Jizan (Saudi Arabia), southern Red Sea, at a depth of 60-67 m; two specimens trawled off southwest of Ayeyarwady Delta, Myanmar, at 54-129 m; and two specimens trawled off Western Australia at 166 m. The new species shares characters with the modified 'talboti look-alikes' species group (i.e., A. caudicinctus, A. dianthus and A. soloriens) as well as A. rubrifuscus and A. deetsie (both previously also assigned to the latter species group) in having two supraneurals, 12 pectoral-fin rays (13 rays in A. soloriens), and an enlarged, membranous, ventral preopercular edge. Molecular phylogenetic analysis of the apogonid tribe Apogonini, however, revealed that A. fugax n. sp. and its most closely related congeners, A. deetsie and A. rubrifuscus, form a separate phylogenetic clade unrelated to that formed by the 'talboti look-alikes' species group that is part of the A. unicolor species group. Apogon fugax n. sp. is distinguished from the species of the 'talboti look-alikes' species group, A. deetsie and A. rubrifuscus, in having a large head (2.2-2.4 in SL versus 2.4-2.8 in SL), longer first dorsal-fin spine (1.7-2.0 versus 2.7-4.0 in length of the second spine), and in their gill rakers count (developed gill rakers on the first gill arch 11-12 versus 8-9 in A. soloriens and 13-20 in the other four species).

Effects of gonadectomy and dihydrotestosterone on neuronal plasticity in motivation and reward related brain regions in the male rat.

Gonadal hormones affect neuronal morphology to ultimately regulate behaviour. In female rats, oestradiol mediates spine plasticity in hypothalamic and limbic brain structures, contributing to long-lasting effects on motivated behaviour. Parallel effects of androgens in male rats have not been extensively studied. Here, we investigated the effect of both castration and androgen replacement on spine plasticity in the nucleus accumbens shell and core (NAcSh and NAcC), caudate putamen (CPu), medial amygdala (MeA) and medial preoptic nucleus (MPN). Intact and castrated (gonadectomy [GDX]) male rats were treated with dihydrotestosterone (DHT, 1.5mg) or vehicle (oil) in three experimental groups: intact-oil, GDX-oil and GDX-DHT. Spine density and morphology, measured 24hours after injection, were determined through three-dimensional reconstruction of confocal z-stacks of DiI-labelled dendritic segments. We found that GDX decreased spine density in the MPN, which was rescued by DHT treatment. DHT also increased spine density in the MeA in GDX animals compared to intact oil-treated animals. By contrast, DHT decreased spine density in the NAcSh compared to GDX males. No effect on spine density was observed in the NAcC or CPu. Spine length and spine head diameter were unaffected by GDX and DHT in the investigated brain regions. In addition, immunohistochemistry revealed that DHT treatment of GDX animals rapidly increased the number of cell bodies in the NAcSh positive for phosphorylated cAMP response-element binding protein, a downstream messenger of the androgen receptor. These findings indicate that androgen signalling plays a role in the regulation of spine plasticity within neurocircuits involved in motivated behaviours.

Application of multimicroscopic techniques (LM and SEM) in comparative palynological study of Asteroideae members, inhabited in Pakistan.

In the present study light and scanning electron microscopic approaches were used to study the palynological variations among 30 Asteroideae members. Variety of qualitative and quantitative palynological characters like pollen shape and type, pollen sculpturing, pollen size, P/E ratio, exine and intine thickness, interspecific difference, colpi size, pore size, spines length, spine width, and pollen fertility were observed. Results reported remarkable variations among pollen characters of studied taxa. The shape of pollen grains in polar and equatorial views varied from specie to specie such as spheroidal, prolate, oblate, subspheroidal, oblate spheroidal, prolate spheroidal, suboblate, and sub prolate. Bidens pilosa L. showed maximum pollen size in both polar and equatorial views, whereas minimum pollen size in polar view was found in Tetraneuris scaposa (DC.) Greene. (i.e., 30.5 μm) and in equatorial view was found in Cosmos sulphureus Cav. (25.5 μm).The highest P/E ratio (1.39 μm) was measured in Glebionis coronaria L. The values of exine and intine thickness also varied. Tricolporate, tetracolporate, trizonocolporate, pentoporate, and polypentoporate pollen types were examined. Spinateand echinate pollen sculpturingobserved under SEM. Variations in spine length and width also recorded. The maximum pollen fertility (98%) was measured in Chrysanthemum morifolium Ramat. and the lowest (56%) was recorded in Thymophylla tenuiloba (DC.) Small. It was concluded that the variations in qualitative and quantitative characters were seemed to be valuable for the taxonomic investigations of Asteroideae taxa.

Taxonomic significance of vertebral column and caudal skeleton of clupeid fishes (Teleostei: Clupeiformes) of Iran

AbstractClupeiformes (generally known as herrings, shads and sardines) with a synapomorphy of recessus lateralis are globally distributed marine, freshwater and diadromous species classified in seven families including the family Clupeidae. In this study, a comparative analysis of the vertebral column and caudal skeleton of twelve clupeid species was conducted on the basis of X‐ray imaging and usual staining method of bones and cartilages. Several osteological features including number of principal branched caudal rays bearing with hypurals on both lobes of the caudal‐fin; number, length, arrangement and shape of epural bones; shape and length of haemal and neural spines of the penultimate vertebrae 2, 3 and 4; length and shape of parhypural; length and shape of neural arch of the urostyle; distribution of the dorsal and procurrent rays, and fusion of parhypural with preural centrum 1 (PU1) were investigated and a detailed account of these structures were provided. The results reveal that the neural spine of the 2nd, 3rd and 4th penultimate vertebrae (NSPU2, NSPU3 and NSPU4) was generally narrow and broad in lower and pointed at upper part with some variation in the size and position related to the dorsal edge of the body in different taxa. The neural arch of the urostyle (Na) has been observed as spindle, lance‐like or knife‐like. It is usually long (≥1/2 length of the NSPU2) with some modification in the studied species. Two or three curved, straight, cone‐shape or pin‐shaped epurals were found in all species with the same number in congeneric species. Opisthural cartilage (O) lays between HYP6 and PLS anteriorly, located at the tip of PLS or traversed horizontally. The presence of this cartilage made a gap between first (longest) and second unbranched caudal rays in upper part of caudal‐fin. It showed six varied shapes (e.g. fusiform, golf club‐like, horn shape, trapezoid shape, crescent and triangle) with different size in comparison with HYP6. This comparative study revealed that some osteological characters such as shape and position of opisthural cartilage, shape of neural arch of the urostyle, and number of epurals could be used as suitable features for the identification of the studied clupeids at the species and genus levels. The improved knowledge of the skeletal structures provided here, can also facilitate the correct identification of clupeid fossils.

Data on Herbivore Performance and Plant Herbivore Damage Identify the Same Plant Traits as the Key Drivers of Plant–Herbivore Interaction

Simple SummaryOur aim was to determine the effects of a free-living leaf-chewing generalist caterpillar on leaf damage of several different closely related plant species. Herbivore performance and leaf damage were affected by similar plant traits. Traits related to higher caterpillar mortality (higher leaf dissection, number, length and toughness of spines and lower trichome density) also led to higher leaf damage. Both types of data may be used to identify the key traits driving the interactions. On the other hand, we confirmed that it is very important to carefully distinguish whether the data on leaf damage were obtained in the field or in controlled feeding experiments, as the patterns expected in the two environments go in opposite directions.Data on plant herbivore damage as well as on herbivore performance have been previously used to identify key plant traits driving plant–herbivore interactions. The extent to which the two approaches lead to similar conclusions remains to be explored. We determined the effect of a free-living leaf-chewing generalist caterpillar, Spodoptera littoralis (Lepidoptera: Noctuidae), on leaf damage of 24 closely related plant species from the Carduoideae subfamily and the effect of these plant species on caterpillar growth. We used a wide range of physical defense leaf traits and leaf nutrient contents as the plant traits. Herbivore performance and leaf damage were affected by similar plant traits. Traits related to higher caterpillar mortality (higher leaf dissection, number, length and toughness of spines and lower trichome density) also led to higher leaf damage. This fits with the fact that each caterpillar was feeding on a single plant and, thus, had to consume more biomass of the less suitable plants to obtain the same amount of nutrients. The key plant traits driving plant–herbivore interactions identified based on data on herbivore performance largely corresponded to the traits identified as important based on data on leaf damage. This suggests that both types of data may be used to identify the key plant traits determining plant–herbivore interactions. It is, however, important to carefully distinguish whether the data on leaf damage were obtained in the field or in a controlled feeding experiment, as the patterns expected in the two environments may go in opposite directions.

Morphology of testate amoeba Difflugia australis (Playfair, 1918) Gautier-Lièvre et Thomas, 1958 from a subtropical reservoir (southeast China)

Difflugia australis, first described by Playfair (1918), has a unique morphotype. However, in the absence of morphometric data, it has not yet been reliably classified within the largest testate amoeba genus Difflugia. In this study D. australis collected from a subtropical reservoir in southeast China was investigated by means of light and scanning electron microscopy. Basing on biometrical data, we provide an improved diagnosis of this little known species. Difflugia australis is different from other similar congeners (i.e., D. bacillariarum Perty, 1849 and D. elegans Penard, 1890) mainly by the combination of the following features: the shell is broadly ovate, with rounded dome and convex sides converging down to a very short distance from the aperture and diverging suddenly into a short rim (collar). It is usually more or less asymmetrical, with one side being more dilated than the other. The shell surface is slightly smooth, composed of flat siliceous plates of irregular shape and size, mixed with fine grains; microbial spores of comparable forms are spread on the shell surface; particles are often interspersed with a network of organic cement with unique mesh pattern; one (sometimes two) slanting spine-like posterior end of the shell is variable in form; collar is mainly formed by small plates of equal size. The dimensions of the shell are: total shell length 88–106 µm; shell width 53–88 µm; aperture diameter 19–28 µm; collar height 3–6 µm; spine length 3‒23 μm. The size frequency distributions of both total shell length and shell width indicate that it is a size-monomorphic species with low variability.

KLHL17/Actinfilin, a brain-specific gene associated with infantile spasms and autism, regulates dendritic spine enlargement

BackgroundDendritic spines, the actin-rich protrusions emerging from dendrites, are the subcellular locations of excitatory synapses in the mammalian brain. Many actin-regulating molecules modulate dendritic spine morphology. Since dendritic spines are neuron-specific structures, it is reasonable to speculate that neuron-specific or -predominant factors are involved in dendritic spine formation. KLHL17 (Kelch-like 17, also known as Actinfilin), an actin-binding protein, is predominantly expressed in brain. Human genetic study has indicated an association of KLHL17/Actinfilin with infantile spasms, a rare form of childhood epilepsy also resulting in autism and mental retardation, indicating that KLHL17/Actinfilin plays a role in neuronal function. However, it remains elusive if and how KLHL17/Actinfilin regulates neuronal development and brain function.MethodsFluorescent immunostaining and electrophysiological recording were performed to evaluate dendritic spine formation and activity in cultured hippocampal neurons. Knockdown and knockout of KLHL17/Actinfilin and expression of truncated fragments of KLHL17/Actinfilin were conducted to investigate the function of KLHL17/Actinfilin in neurons. Mouse behavioral assays were used to evaluate the role of KLHL17/Actinfilin in brain function.ResultsWe found that KLHL17/Actinfilin tends to form circular puncta in dendritic spines and are surrounded by or adjacent to F-actin. Klhl17 deficiency impairs F-actin enrichment at dendritic spines. Knockdown and knockout of KLHL17/Actinfilin specifically impair dendritic spine enlargement, but not the density or length of dendritic spines. Both N-terminal Broad-Complex, Tramtrack and Bric-a-brac (BTB) domain and C-terminal Kelch domains of KLHL17/Actinfilin are required for F-actin remodeling and enrichment at dendritic spines, as well as dendritic spine enlargement. A reduction of postsynaptic and presynsptic markers at dendritic spines and altered mEPSC profiles due to Klhl17 deficiency evidence impaired synaptic activity in Klhl17-deficient neurons. Our behavioral assays further indicate that Klhl17 deficiency results in hyperactivity and reduced social interaction, strengthening evidence for the physiological role of KLHL17/Actinfilin.ConclusionOur findings provide evidence that KLHL17/Actinfilin modulates F-actin remodeling and contributes to regulation of neuronal morphogenesis, maturation and activity, which is likely relevant to behavioral impairment in Klhl17-deficient mice.Trial registration Non-applicable.

The late‐onset Alzheimer's disease genetic risk factor CD2AP impacts synapses via actin dynamics

AbstractBackgroundIn late‐onset Alzheimer’s disease (LOAD) the causal mechanisms of synaptic dysfunction that underlie the memory deficits that lead to dementia are not established. The search for genetic risk factors in LOAD led to the identification of more than 20 genes and three main mechanisms: endocytic trafficking, lipid metabolism and immune response. Here we aim to establish causality between a mutation in CD2AP, one of the endocytic trafficking risk factors, and synaptic dysfunction. Since CD2AP is a regulator of the actin cytoskeleton dynamics which is essential for spine morphology, we hypothesize that a LOAD mutation CD2AP may impact spines by deregulating actin.MethodWe have analyzed synapses and spines density as well as spinal actin in cortical mouse primary neurons either transiently overexpressing wild‐type and mutant CD2AP‐GFP as well as GFP as control or infected with lentivirus expressing GFP and shCD2AP or non‐targeting shRNA as control. Moreover, we investigated CD2AP synaptic localization by immunofluorescence microscopy. We used quantitative single‐cell analysis using ICY and Imaris software.ResultWe discovered that a pool of CD2AP is present in spines; and that both CD2AP wild‐type and mutant are significantly enriched in spines. Spines length decreased with larger spine heads, by CD2AP wild‐type and more pronouncedly by mutant CD2AP overexpression. Indicating that CD2AP might function at synapses, by regulating spine morphology. Indeed, synapses density was reduced by CD2AP knockdown. Mechanistically, we found that spinal F‐actin increased by CD2AP wild‐type and more pronouncedly by mutant CD2AP overexpression compared to control neurons. We are currently investigating whether spinal F‐actin is altered by CD2AP knockdown.ConclusionThese results indicate that CD2AP regulates spine morphology and thus synapses. A LOAD mutant CD2AP may interfere with its function by dysregulating actin dynamics at spines. Overall CD2AP variants may contribute to LOAD development by directly interfering with synapses.

UV radiation affects antipredatory defense traits in Daphnia pulex.

In aquatic environments, prey perceive predator threats by chemical cues called kairomones, which can induce changes in their morphology, life histories, and behavior. Predator‐induced defenses have allowed for prey, such as Daphnia pulex, to avert capture by common invertebrate predators, such as Chaoborus sp. larvae. However, the influence of additional stressors, such as ultraviolet radiation (UVR), on the Daphnia–Chaoborus interaction is not settled as UVR may for instance deactivate the kairomone. In laboratory experiments, we investigated the combined effect of kairomones and UVR at ecologically relevant levels on induced morphological defenses of two D. pulex clones. We found that kairomones were not deactivated by UVR exposure. Instead, UVR exposure suppressed induced morphological defense traits of D. pulex juveniles under predation threat by generally decreasing the number of neckteeth and especially by decreasing the size of the pedestal beneath the neckteeth. UVR exposure also decreased the body length, body width, and tail spine length of juveniles, likely additionally increasing the vulnerability to Chaoborus predation. Our results suggest potential detrimental effects on fitness and survival of D. pulex subject to UVR stress, with consequences on community composition and food web structure in clear and shallow water bodies.

Parascolopsis akatamae, a new species of dwarf monocle bream (Perciformes: Nemipteridae) from the Indo-West Pacific, with redescription of closely related species P. eriomma.

A new species of dwarf monocle bream, Parascolopsis akatamae n. sp., is described from the Indo-West Pacific. The new species is distinguished from all other species of Parascolopsis in having 16-19 gill rakers on the first arch, length of forked part of caudal fin 5.8-6.5 times in standard length, eye diameter 1.3-1.8 times in length of the longest dorsal-fin spine, and a pale yellow stripe present from lower edge of the eye to posterior edge of the preopercle. Parascolopsis eriomma (Jordan Richardson, 1909) is morphologically very similar to the new species and the two have been confused with each other for a long time. Therefore, we redescribe P. eriomma based on the holotype and newly collected specimens. In addition, we found that patterns of biofluorescence emission for both species are clearly different. This suggests that their biofluorescence patterns may function in distinguishing each other.

Altered synaptic ultrastructure in the prefrontal cortex of Shank3-deficient rats

BackgroundDeletion or mutations of SHANK3 lead to Phelan–McDermid syndrome and monogenic forms of autism spectrum disorder (ASD). SHANK3 encodes its eponymous scaffolding protein at excitatory glutamatergic synapses. Altered morphology of dendrites and spines in the hippocampus, cerebellum, and striatum have been associated with behavioral impairments in Shank3-deficient animal models. Given the attentional deficit in these animals, our study explored whether deficiency of Shank3 in a rat model alters neuron morphology and synaptic ultrastructure in the medial prefrontal cortex (mPFC).MethodsWe assessed dendrite and spine morphology and spine density in mPFC layer III neurons in Shank3-homozygous knockout (Shank3-KO), heterozygous (Shank3-Het), and wild-type (WT) rats. We used electron microscopy to determine the density of asymmetric synapses in mPFC layer III excitatory neurons in these rats. We measured postsynaptic density (PSD) length, PSD area, and head diameter (HD) of spines at these synapses.ResultsBasal dendritic morphology was similar among the three genotypes. Spine density and morphology were comparable, but more thin and mushroom spines had larger head volumes in Shank3-Het compared to WT and Shank3-KO. All three groups had comparable synapse density and PSD length. Spine HD of total and non-perforated synapses in Shank3-Het rats, but not Shank3-KO rats, was significantly larger than in WT rats. The total and non-perforated PSD area was significantly larger in Shank3-Het rats compared to Shank3-KO rats. These findings represent preliminary evidence for synaptic ultrastructural alterations in the mPFC of rats that lack one copy of Shank3 and mimic the heterozygous loss of SHANK3 in Phelan–McDermid syndrome.LimitationsThe Shank3 deletion in the rat model we used does not affect all isoforms of the protein and would only model the effect of mutations resulting in loss of the N-terminus of the protein. Given the higher prevalence of ASD in males, the ultrastructural study focused only on synaptic structure in male Shank3-deficient rats.ConclusionsWe observed increased HD and PSD area in Shank3-Het rats. These observations suggest the occurrence of altered synaptic ultrastructure in this animal model, further pointing to a key role of defective expression of the Shank3 protein in ASD and Phelan–McDermid syndrome.

Taxonomic Notes on Juvenile Homolax megalops (Alcock 1894) from Kollam, Southwest Coast of India, Arabian Sea

The present study reports the taxonomic notes on Homolax megalops (Alcock 1894) off Kollam, Southeastern Arabian Sea. Homolax displayed close relationship with Paromola species, even though these were found to differ with respect to the length of pseudorostral spines. Additionally, the study documented the DNA sequences and genetic divergence between the genus Homolax and Homola (COI: 27.3%). Phylogenetic relationship of Homolidae with available 16S sequences from GenBank was also documented..

Sex difference in cerebrospinal fluid/blood albumin quotients in patients with schizophreniform and affective psychosis

BackgroundThe importance of cerebrospinal fluid (CSF) diagnostics for psychiatry is growing. The CSF/blood albumin quotient (QAlb) is considered to be a measure of the blood–CSF barrier function. Recently, systematically higher QAlb in males than in females was described in neurological patients. The aim of this study was to investigate whether a sex difference could also be detected in a well-characterized psychiatric cohort.MethodsThe patient cohort comprised 989 patients, including 545 females and 444 males with schizophreniform and affective syndromes who underwent CSF diagnostics, including QAlb measurement. The basic CSF findings and antineuronal autoantibody data of this cohort have already been published. This re-analysis employed analysis of covariance with age correction for QAlb mean values and chi2-testing for the number of increased age-corrected QAlb levels to investigate sex differences in QAlb.ResultsThe QAlb levels were elevated above reference levels by 18% across all patients, and a comparison between male and female patients revealed a statistically significant sex difference, with increased values in 26% of male patients and a corresponding rate of only 10% in female patients (chi2 = 42.625, p < 0.001). The mean QAlb values were also significantly higher in males (6.52 ± 3.69 × 10–3) than in females (5.23 ± 2.56 × 10–3; F = 52.837, p < 0.001).DiscussionThe main finding of this study was a significantly higher QAlb level in male compared to female patients with psychiatric disorders, complementing previously described sex differences in neurological patient cohorts. This result indicates bias from some general factors associated with sex and could be partly explained by sex differences in body height, which is associated with spine length and thus a longer distance for CSF flow within the subarachnoid space down the spine from the occipital area to the lumbar puncture site in males compared to females. Hormonal influences caused by different estrogen levels and other sex-specific factors could also play a relevant role. The significance of the study is limited by its retrospective design, absence of a healthy control group, and unavailability of exact measures of spine length.

New species and records of Cloeodes Traver, 1938 (Ephemeroptera, Baetidae) from Costa Rica.

The nymph of Cloeodes dantasp. nov. is described from male and female nymphs collected from highland streams in the Caribbean Slope of the Costa Rica Central Volcanic Mountain Range. Adults are unknown. In addition, C. excogitatus and C. redactus are recorded for the first time in the country. Cloeodes dantasp. nov. can be differentiated from all described species by the predominantly brownish coloration on females and a similar coloration on males but with segments VII–IX light yellow and light brown, with no conspicuous marks or patterns; abundant scale-bases throughout most parts of the body; hindwings pads absent; the presence of three spines in the corners of the posterior margin of sternum III, and the posterior margin of tergum III with 28–30 spines on each side of the middle line (spine with a base width up to 0.5× spine length).

Adult moulting and dimorphism in a new species of Sphenoderes (Kinorhyncha: Kentrorhagata)—Is the exception becoming the rule?

AbstractAdult dimorphism (i.e. non‐sexual dimorphism observed among sexually mature specimens) and the existence of two morphologically distinct adult stages are for the first time reported from a species of the kentrorhagid kinorhynch genus Sphenoderes. The dimorphism was found in a new species, Sphenoderes neptunus sp. nov., from the Gulf of Naples, Italy, and a formal description is provided. While dimorphism between adult life stages of kinorhynchs so far have been restricted to differences in the two posteriormost segments, the dimorphism in the new species is expressed in spine lengths throughout the entire trunk, as well as in presence or absence of cuspidate spines. The implications for comparative kinorhynch morphology and taxonomy are discussed, and it is concluded that adult dimorphism and the occurrence of more than one adult life stage always should be considered as a possibility when exploring kinorhynchs of the orders Kentrorhagata and Xenosomata. Despite the comparative challenges prompted by the adult dimorphism, species of Sphenoderes can still be distinguished by differences in shape of midventral placid and distribution of sensory spots. Conversely, spine patterns as differential characters should be used with caution, and only after ensuring that specimens belonging to the same adult stage are compared.