Intraovarian sperm storage in Helicolenus dactylopterus dactylopterus fertilitzation, crypt formation and maintenance of stored sperm

The females of the bluemouth rockfish, Helicolenus dactylopterus dactylopterus (DelaRoche, 1809), store sperm within their ovaries for periods of up to 10 months. Twenty six females with standard lengths between 152 and 257 mm and six males with standard lengths between 253 and 209 mm were caught storage crypts with stored spermatozoa and to describe their evolution over the year. After internal fertilization and once sperm reaches the ovary, a crypt forms probably by an epithelial inclusion at the base of the lamellae of one or several spermatozoa groups that are floating freely in the interlamellar space of the ovarian lumen. Stored spermatozoa have a large cytoplasm bag surrounding their heads. This bag could serve as a nutritive reservoir during the long storage period. Many desmosonal and tight junctions between the crypt cells ensure tha male sex cells are protected against the female immune system

Spermiogenesis particularities of a sperm storage species: Helicolenus dactylopterus (Teleostei: Scorpaenidae)

A study of the spermiogenesis and spermatozoa of Helicolenus dactylopterus was conducted. Females of this species have the capacity to store sperm within their ovaries, and male gametes have a considerable cytoplasmic mass surrounding their heads to survive the long period of intraovarian sperm storage. Our observations show that early spermatids are round-shaped cells and have a spherical nucleus with diffuse chromatin. The nuclear volume decreases as a result of progressive chromatin condensation during spermiogenesis, causing the nucleus to take on a U-shape. Flagellar insertion is not central to the nucleus but consistently occurs at an oblique angle towards one side of it. The flagellum is inserted into the nuclear fossa, without subsequent nuclear rotation. In mature spermatozoa, the flagellum is adjacent to the nucleus. A comparison of the spermatozoa in the testicular lobules and those in the intraovarian storage structures suggests that the increase in volume of the cytoplasmic mass may occur in the posterior region of the testis, in the testicular duct. Spermatozoa enter the ovary in groups that reach the ovarian lumen and are surrounded by the ovarian epithelium for storage in sperm storage crypts

Efficient priority rules

We study the assignment of indivisible objects with quotas (houses, jobs, or offices) to a set of agents (students, job applicants, or professors). Each agent receives at most one object and monetary compensations are not possible. We characterize efficient priority rules by efficiency, strategy-proofness, and renegotiation-proofness. Such a rule respects an acyclical priority structure and the allocations can be determined using the deferred acceptance algorithm.

Consumers’ sensory acceptability of pork from immunocastrated male pigs

Boar taint is the off-odour or off flavour of cooked pork. Currently, the most common method of controlling boar taint is surgical castration. However, immunocastration has been used in some parts of the world as an alternative to surgical castration. The aim of this study was to evaluate the sensory acceptability of meat from immunocastrated pigs (IM) compared with meat from females (FE), surgically castrated (CM) and entire males (EM). Twenty animals of each type were evaluated by 201 consumers in 20 sessions. Longissimus thoracis muscle of the different animals was cooked in an oven at 180 °C for 10 min. Consumers scored the odour and the flavour of the meat in a 9-point category scale without an intermediate level. There were no significant differences in consumer’s evaluation of meat from IM, CM, and FE. In contrast, EM meat presented a higher percentage of dissatisfied scores and was significantly (P & 0.05) less accepted than meat from CM, IM and FE. Consumers’ acceptability of EM meat was always lower, independently of its androstenone levels. However meat with low levels of androstenone was more accepted that meat with medium or high levels of this substance. It can be concluded that immunocastration produced pork that was accepted by the consumers, and was indistinguishable from pork from CM or FE.

Estudi de l'organogènesi del sistema reproductor de la cabra de mar (Maja brachydactyla) i efecte dels factors ambientals sobre la reproducció en captivitat

Diferents aspectes de la reproducció de la cabra de mar Maja brachydactyla s’han estudiat amb l’objectiu d’obtenir coneixements bàsics i aplicats al cultiu en captivitat d’aquesta espècie de gran interès comercial i aqüícola. L’anatomia interna de l’aparell reproductor masculí, el procés d’espermatogènesi, amb especial èmfasi amb la formació de l’acrosoma, i l’estructura i organització l’espermatozoide s’han descrit amb tècniques microscòpiques avançades. El desenvolupament de les gònades durant els primeres fases del desenvolupament post- embrionari (fases larvàries i primer cranc juvenil) han estat descrites mitjançant la quantificació de l’expressió del gen vasa, el qual és expressat específicament per les cèl•lules de la línia germinal. Aquests coneixements són bàsics per a la comprensió del paper dels mascles en la la reproducció i la seva aplicació posterior en condicions de captivitat. La reproducció en captivitat s’ha estudiat amb una sèrie d’experiments amb l’objectiu de determinar la quantitat, pes sec i composició bioquímica proximal de les larves acabades d’eclosionar en condicions de captivitat i l’efecte de les condicions ambientals, com ara el fotoperíode i la salinitat, sobre aquests paràmetres. Aquests experiments demostren què es poden obtenir larves de la cabra de mar en condicions de captivitat què podrien ser utilitzades per a la producció i l’efecte sobre la reproducció del fotoperíode i salinitat.

Sperm Ultrastructure of the Spider Crab Maja brachydactyla (Decapoda: Brachyura)

This study describes the morphology of the sperm cell of Maja brachydactyla, with emphasis on localizing actin and tubulin. The spermatozoon of M. brachydactyla is similar in appearance and organization to other brachyuran spermatozoa. The spermatozoon is a globular cell composed of a central acrosome, which is surrounded by a thin layer of cytoplasm and a cup-shaped nucleus with four radiating lateral arms. The acrosome is a subspheroidal vesicle composed of three concentric zones surrounded by a capsule. The acrosome is apically covered by an operculum. The perforatorium penetrates the center of the acrosome and has granular material partially composed of actin. The cytoplasm contains one centriole in the subacrosomal region. A cytoplasmic ring encircles the acrosome in the subapical region of the cell and contains the structures-organelles complex (SO-complex), which is composed of a membrane system, mitochondria with few cristae, and microtubules. In the nucleus, slightly condensed chromatin extends along the lateral arms, in which no microtubules have been observed. Chromatin fibers aggregate in certain areas and are often associated with the SO-complex. During the acrosomal reaction, the acrosome could provide support for the penetration of the sperm nucleus, the SO-complex could serve as an anchor point for chromatin, and the lateral arms could play an important role triggering the acrosomal reaction, while slightly decondensed chromatin may be necessary for the deformation of the nucleus.

Male vs Female Lupus. A comparison of ethnicity, clinical features, serology and outcome over a 30 year period

Un estudi observacional de pacients amb LES, atesos al University College de London Hospital entre 1976 i 2005, es va dur a terme per revisar les diferències entre homes i dones amb lupus pel que fa a les característiques clíniques, serologia i resultats. 439 dones i 45 homes van ser identificats. L'edat mitjana al diagnòstic va ser de 29,3 anys (12,6), sense diferències significatives entre homes i dones. El sexe femení es va associar significativament amb la presència d'úlceres orals i Ig M ACA. No hi va haver diferències significatives en la comparació de les altres variables. Durant aquest període de seguiment de trenta anys, relativament poques diferències han sorgit al comparar les freqüències de les característiques clíniques i serològiques en homes y dones amb lupus.

Estudi del sistema reptroductor de la guatlla (Coturnix coturnix) i de la hibridació amb la guatlla japonesa (Coturnix japonica) domèstica i híbrids

La guatlla (Coturnix coturnix) és actualment una espècie amb un estat de conservació desfavorable. Una amenaça per a la seva conservació és la hibridació que pot produir-se degut als alliberaments massius amb finalitats cinegètiques de la guatlla japonesa (Coturnix japonica) o híbrids provinents de granges de cria. Els objectius d’estudi són: a) Aprofundir en el sistema sexual de la guatlla, ja que el seu coneixement pot permetre entendre els mecanismes d’hibridació amb la guatlla japonesa o híbrids. b) Conèixer la taxa de supervivència i l’eficàcia biològica dels individus no nadius a àrees de reproducció de la guatlla. c) Buscar evidències directes d’hibridació en condicions naturals i caracteritzar-la. d) Determinar si existeix competència espermàtica interespecífica mitjançant experiments en captivitat. S’ha seguit el comportament en condicions naturals de parelles homospecífiques i heterospecífiques de mascles i femelles de guatlla i de guatlla japonesa o híbrids. S’ha analitzat la paternitat dels polls d’aquestes parelles i s’ha pogut conèixer quins aspectes del comportament (segons l’espècie) es relacionen amb l’eficàcia biològica dels adults. S’han analitzat el mateix tipus de dades obtingudes durant cinc temporades reproductives, en les que hi van participar només individus de guatlla. Així s’ha pogut comparar el comportament de l’espècie en presència i absència dels individus al•lòctons. Els resultats indiquen que existeixen dues estratègies sexuals entre els mascles de guatlla. L’estat físic del mascle en relació al dels altres mascles coetanis i el temps de permanència amb la femella determinen la seva taxa de paternitat. Existeix una fracció relativament petita però significativa de guatlla japonesa de granja que sobreviu en condicions naturals i s’hibrida amb la guatlla silvestre, predominantment de forma unidireccional, entre femella japonesa i mascle de guatlla. Aquestes femelles presenten un sistema d’aparellament majoritàriament monògam. Els anàlisis sobre els experiments de competència espermàtica s’estan realitzant a l’actualitat.

Locating emergency services with priority rules: The priority queuing covering location problem

One of the assumptions of the Capacitated Facility Location Problem (CFLP) is thatdemand is known and fixed. Most often, this is not the case when managers take somestrategic decisions such as locating facilities and assigning demand points to thosefacilities. In this paper we consider demand as stochastic and we model each of thefacilities as an independent queue. Stochastic models of manufacturing systems anddeterministic location models are put together in order to obtain a formula for thebacklogging probability at a potential facility location.Several solution techniques have been proposed to solve the CFLP. One of the mostrecently proposed heuristics, a Reactive Greedy Adaptive Search Procedure, isimplemented in order to solve the model formulated. We present some computationalexperiments in order to evaluate the heuristics performance and to illustrate the use ofthis new formulation for the CFLP. The paper finishes with a simple simulationexercise.

Locating emergency services with different priorities: The priority queuing covering location problem

Previous covering models for emergency service consider all the calls to be of the sameimportance and impose the same waiting time constraints independently of the service's priority.This type of constraint is clearly inappropriate in many contexts. For example, in urban medicalemergency services, calls that involve danger to human life deserve higher priority over calls formore routine incidents. A realistic model in such a context should allow prioritizing the calls forservice.In this paper a covering model which considers different priority levels is formulated andsolved. The model heritages its formulation from previous research on Maximum CoverageModels and incorporates results from Queuing Theory, in particular Priority Queuing. Theadditional complexity incorporated in the model justifies the use of a heuristic procedure.

Minimum price variations, time priority and quotes dynamics

We analyze the impact of a minimum price variation (tick) and timepriority on the dynamics of quotes and the trading costs when competitionfor the order flow is dynamic. We find that convergence to competitiveoutcomes can take time and that the speed of convergence is influencedby the tick size, the priority rule and the characteristics of the orderarrival process. We show also that a zero minimum price variation is neveroptimal when competition for the order flow is dynamic. We compare thetrading outcomes with and without time priority. Time priority is shownto guarantee that uncompetitive spreads cannot be sustained over time.However it can sometimes result in higher trading costs. Empiricalimplications are proposed. In particular, we relate the size of thetrading costs to the frequency of new offers and the dynamics of theinside spread to the state of the book.

Spermiogenesis and spermatozoon ultrastructure of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Gadiformes: Merlucciidae)

Spermiogenesis and the ultrastructure of the spermatozoon of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Linnaeus, 1758), have been studied by means of transmission electron microscopy. Spermiogenesis involves firstly the formation of a differentiation zone. It is characterized by the presence of two centrioles associated with striated rootlets, an intercentriolar body and an electron-dense material in the apical region of this zone. Later, two flagella develop from the centrioles, growing orthogonally in relation to the median cytoplasmic process. Flagella then undergo a rotation of 90° until they become parallel to the median cytoplasmic process, followed by the proximodistal fusion of the flagella with the median cytoplasmic process. The nucleus elongates and afterwards it migrates along the spermatid body. Spermiogenesis finishes with the appearance of the apical cone surrounded by the single helical crested body at the base of the spermatid. Finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of C. crassiceps is filiform and contains two axonemes of the 9 + '1' trepaxonematan pattern, a parallel nucleus, parallel cortical microtubules, and electron-dense granules of glycogen. The anterior extremity of the gamete exhibits a short electron-dense apical cone and one crested body, which turns once around the sperm cell. The first axoneme is surrounded by a ring of thick cortical microtubules that persist until the appearance of the second axoneme. Later, these thick cortical microtubules disappear and thus, the mature spermatozoon exhibits two bundles of thin cortical microtubules. The posterior extremity of the male gamete presents only the nucleus. Results are discussed and compared particularly with the available ultrastructural data on the former 'pseudophyllideans'. Two differences can be established between spermatozoa of Bothriocephalidea and Diphyllobothriidea, the type of spermatozoon (II vs I) and the presence/absence of the ring of cortical microtubules.

Spermiogenesis and spermatozoon ultrastructure of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Gadiformes: Merlucciidae)

Spermiogenesis and the ultrastructure of the spermatozoon of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Linnaeus, 1758), have been studied by means of transmission electron microscopy. Spermiogenesis involves firstly the formation of a differentiation zone. It is characterized by the presence of two centrioles associated with striated rootlets, an intercentriolar body and an electron-dense material in the apical region of this zone. Later, two flagella develop from the centrioles, growing orthogonally in relation to the median cytoplasmic process. Flagella then undergo a rotation of 90° until they become parallel to the median cytoplasmic process, followed by the proximodistal fusion of the flagella with the median cytoplasmic process. The nucleus elongates and afterwards it migrates along the spermatid body. Spermiogenesis finishes with the appearance of the apical cone surrounded by the single helical crested body at the base of the spermatid. Finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of C. crassiceps is filiform and contains two axonemes of the 9 + '1' trepaxonematan pattern, a parallel nucleus, parallel cortical microtubules, and electron-dense granules of glycogen. The anterior extremity of the gamete exhibits a short electron-dense apical cone and one crested body, which turns once around the sperm cell. The first axoneme is surrounded by a ring of thick cortical microtubules that persist until the appearance of the second axoneme. Later, these thick cortical microtubules disappear and thus, the mature spermatozoon exhibits two bundles of thin cortical microtubules. The posterior extremity of the male gamete presents only the nucleus. Results are discussed and compared particularly with the available ultrastructural data on the former 'pseudophyllideans'. Two differences can be established between spermatozoa of Bothriocephalidea and Diphyllobothriidea, the type of spermatozoon (II vs I) and the presence/absence of the ring of cortical microtubules.

Identifying the parent-of-origin of de novo SNVs in schizophrenia

Several studies over the last few years have shown that newly arising (de novo) mutations contribute to the genetics of schizophrenia (SZ), autism (ASD) and other developmental disorders. The strongest evidence comes from studies of de novo Copy Number Variation (CNV), where the rate of new mutations is shown to be increased in cases when compared to controls [23, 24]. Research on de novo point mutations and small insertion-deletions (indels) has been more limited, but with the development of next-generation sequencing (NGS) technology, such studies are beginning to provide preliminary evidence that de novo single-nucleotide mutations (SNVs) might also increase risk of SZ and ASD [25, 26] Advanced paternal age is a major source of new mutations in human beings [27] and could thus be associated with increased risk for developing SZ, ASD or other developmental disorders. Indeed, advanced paternal age is found to be a risk factor for developing SZ and ASD in the offspring [28, 29] and new mutations related to advanced paternal age have been implicated as a cause of sporadic cases in several autosomal dominant diseases, some neurodevelopmental diseases, including SZ and ASD, and social functioning. New single-base substitutions occur at higher rates at males compared to females and this difference increases with paternal age. This is due to the fact that sperm cells go through a much higher number of cell divisions (~840 by the age of 50), which increases the risk for DNA copy errors in the male germ line [30] . By contrast, the female eggs (oocytes) undergo only 24 cell divisions and all but the last occur during foetal life. The aim of my project is to determine the parent-of-origin of de novo SNVs, using large samples of parent-offspring trios affected with schizophrenia (SZ). From whole exome sequencing of 618 Bulgarian proband-offspring trios affected, nearly 1000 de novo (SNVs or small indels) have been identified and from these, the parent-of-origin of at least 60% of the mutations (N=600) can be established. This project is contained in a main one that consists on the determination of the parental origin of different types of de novo mutations (SNVs, small indels and large CNVs).

Depression-like behavior is dependent on age in male SAMP8 mice

Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.