Prenatal origins of brachymesophalangia-5

As shown in 91 embryos and fetuses in the 41–235 mm crown-rump length, brachymesophalangia-5 may be identified in prenatal time. Although the ratios involving different combinations of length of mid-5 relative to other segments yield different frequencies of BMP-5, the short middle segment of the little finger is already associated with clinodactyly and developmental eccentricity as early as the ninth week of prenatal development.     

Scanning electron microscopy substantiates histology in showing the inadequacy of the existing theories on the development of the proximal coronary arteries and their connections with the arterial trunks

Development of proximal coronary arterial segments and coronary arterial orifices was studied by scanning electron microscopy in 20 rat embryos and by light microscopy in serial sections of 20 human and another 18 rat embryos. Neither by scanning electron microscopy nor by light microscopy did we observe more than two coronary arterial orifices. These coronary orifices were always situated in the sinuses of the aorta that faced the pulmonary artery. In the human embryos the coronary orifices emerged between 37-39 days of gestation (16-19 mm crown-rump length, Streeter horizon XVIII-XIX) and were invariably present beyond 39 days (19 mm crown-rump length, Streeter horizon XIX). In rat embryos, the coronary orifices emerged in both scanning electron microscopy and light microscopy at 15-17 days of gestation (13-17 mm crown-rump length) and were invariably present beyond 17 days (17 mm crown-rump length). In both human and rat embryos, either by scanning electron microscopy and light microscopy, the left coronary orifice was observed significantly earlier. In all the investigated embryos, human as well as rat, septation at arterial orifice level was complete, including the earliest stages studied. Light microscopy showed that at the emerging stages of the coronary orifices, the proximal epicardial segments of the left and right coronary arteries could already be identified in a peritruncal ring of epicardial vasculature, before the coronary orifice was observed. This was the case in human as well as in rat embryos. Thus, a coronary orifice was never seen in the absence of a proximal coronary artery. The present theories on development of the proximal coronary arteries and coronary orifices do not offer an adequate explanation for either these data or the known possible congenital abnormalities of the coronary arteries. Our study supports dual proximal coronary arterial development. These two proximal coronary arteries develop out of a peritruncal ring of vascular structures on to the aorta. The process by which the coronary orifices actually develop remains to be explained.     

Development and rudimentation of the peripheral olfactory system in the harbor porpoise Phocoena phocoena (Mammalia: Cetacea)

Serial sections of 13 embryos and fetuses of the harbor porpoise from 10 mm crown-rump length up to 167 mm total length were studied. Unlike the adult animals, ontogenetic stages of 18–27 mm crown-rump length still show a typical mammalian olfactory bulb. The olfactory bulb primordium is penetrated by olfactory nerve fibers, the latter passing through the cribriform plate. However, the olfactory bulb anlage is gradually reduced in later stages, its placodal component being largely uncoupled from the telencephalon. As a ganglionlike structure, the remains of the placodal component stay in contact with the nasal septum and mucosa via thin bundles of nerve fibers. The ganglion and plexus can be traced within the meninges until the adult stage of the porpoise. There is strong evidence that they represent the material of the terminalis system, which cannot be distinguished from the olfactory system in earlier stages. A vomeronasal organ could not be detected in the embryonal and fetal material investigated.     

Non-invasive ultrasonographic characterization of phenotypic changes during embryo development in non-anesthetized mice of different genotypes

This study aimed to determine phenotypic changes during embryo development in the mouse, and the influence of genetic background, by non-invasive real-time ultrasonography. Serial scannings were performed from Day 4.5 after the appearance of the vaginal plug in a total of 34 adult mice of different strains (9BALB/c, 10C57BL/6 and 15 CD1). Embryonic vesicle diameter was measurable from Day 4.5 of pregnancy. Images of embryos were obtainable from Day 5.5 of gestation onwards, and crown-rump length and trunk parameters (diameter and area) were measured. At more advanced stages, the positions of fetuses prevented accurate measurement of crown-rump length; therefore, head diameters (occipito-snout length and biparietal diameter) were used as an alternative index of fetal size. All measurements correlated highly with gestational age (P<0.0005). No significant differences were observed between genotypes in early pregnancy, but during the last week of gestation trunk measurements were larger in CD1 embryos (P<0.05) while head diameters were larger in C57BL/6 conceptuses (P<0.05). There was a significant effect of genetic background on heart rate throughout pregnancy; although heart rate was similar in CD1 and C57BL/6 embryos (154.5+/-2.8 and 147.8+/-4.5 beats/min, respectively), it was significantly lower in BALB/c mice (127.0+/-2.1; P<0.005 vs. CD1 and C57BL/6).     

Fetal development, and placental and maternal plasma concentrations of progesterone in the little brown bat (Myotis lucifugus)

Progesterone concentrations measured in plasma samples from 280 bats captured during pregnancy or early lactation were related to fetal attributes indicative of stage of pregnancy. Fetal weight increased exponentially from 40 mg at crown-rump length of 6 mm to 2000 mg at 23 mm (term). Fetal weights at term accounted for up to 35% of the weight of intact pregnant animals. Progesterone concentrations increased from less than 5 ng/ml at 2 mm estimated crown-rump length to plateau values of approximately 65 ng/ml (geometric means) from 16 mm crown-rump length until the most advanced stages of pregnancy. Mean concentration in 8 post-partum bats, most of which were actively lactating, was 8.4 ng/ml; 11.6 ng/ml was measured in one animal that was carrying a wet neonate when sampled yet was still pregnant when captured 5 h earlier. Placental concentrations of progesterone ranged from 43 to 964 ng/g wet weight of tissue and mean values increased in a similar fashion though were about 4-fold greater than changes in plasma concentrations of the steroid. The concentrations in placental tissue were at least 15- to 20-fold higher than could be expected from blood contamination, indicating that placental steroidogenesis is likely to occur in this species.     

Brain tissue transplanted to the anterior chamber of the eye

Summary Knowing the ontogenesis of the central monoamine neurons of the rat it is possible to obtain, by free-hand dissection from embryos and newly born animals, pieces containing dopamine (DA), noradrenaline (NA), and 5-hydroxytryptamine (5-HT) neurons that are small enough to permit homologous transplantation to the anterior chamber of the eye of adult animals. With this technique it was established that all three types of immature monoamine neurons are able to survive in the anterior chamber. Fluorescence histochemical analysis of whole mount preparations of the sympathetically denervated host irides revealed that both the catecholamine- and the 5-HT-neurons are able to partly reinnervate the irides, forming networks of varicose nerve terminals similar to the normally present sympathetic adrenergic ground plexus.Monoamine nerve cell bodies are attached to the irides but the majority of fluorescent nerve cell bodies is located within the transplants. Serial sectioning of these transplants showed rather well organized brain tissue, containing groups of fluorescent and non-fluorescent cell bodies, many areas being innervated by monoamine nerve terminals. When brain tissue was transplanted before the normal appearance of fluorescent neuroblasts (embryos with a crown-rump length less than 8 mm) monoamine neurons developed and matured within the eye.The amount of newly formed nerves of central origin recovered on the irides increased with time between the 2nd and 4th postoperative week and persisted after 2 months. The yield of new fibers was better using transplants from embryos with a crown-rump length between 15 and 30 mm than using transplants from larger embryos and newly born animals.If embryonic brain tissue known to be devoid of monoamine nerve cell bodies but containing monoamine nerve terminals in the adult state (cortex cerebri and cerebelli, spinal cord) was transplanted to sympathetically non-denervated eyes, the sympathetic adrenergic fibers seemed to be able to innervate the transplants.This work was supported by grants from the Swedish Medical Research Council (14×–3185), Karolinska Institutets fonder, and Magnus Bergvalls Stiftelse. We thank Miss Monica Eliasson, Mrs. Ulla Flyger, Mrs. Barbro Norstedt and Miss Ingrid Strömberg for skilful technical assistance. The generous gifts of Nialamide, Pfizer, and Pargyline, Abbott are gratefully acknowledged.     

Ultrasonography in early pregnancy diagnosis and measurements of fetal size in reindeer (Rangifer tarandus tarandus)

Transrectal or transabdominal examinations of 13 pluriparous reindeer (Rangifer tarandus tarandus) by ultrasonography from the start of mating until week 20 of gestation were conducted to find out when pregnancy could first be detected and to describe fetal development in early pregnancy. The examinations (n=35 per animal) were performed with a 5 MHz linear transducer from 7th October until 1st January and with a 3 MHz sector transducer from that time until 24th February. Time of pregnancy diagnosis by ultrasonography, the first fetal heartbeat and measurements of crown-rump length, chest width and chest depth were recorded during the examinations. Pregnancy was diagnosed by transrectal ultrasonography between the weeks 3 and 7 of gestation. The accuracy of the pregnancy diagnosis, defined as the proportion of females correctly detected to be pregnant, was 15% at week 3, 46% at week 4, 77% at week 5, and 92% at week 6 of gestation. Fetal heartbeat was first detected between the weeks 5 and 8 of gestation. The first measurements of crown-rump length were made on week 3 of gestation, of chest width on week 4 and of chest depth on week 5 of gestation. Chest width and depth were detectable until the end of the study at week 20 of gestation. Transrectal ultrasonography is an efficient tool in early pregnancy diagnosis of reindeer. The fetal growth curves obtained by ultrasonography resembled those obtained in previous morphological studies.     

Growth allometry of the myocardium in human embryos (from stages 15 to 23).

The relative growth of the myocardium was studied in 27 staged human embryos (Carnegie stages). The volume of the myocardium was determined for each embryo according to Cavalieri's principle (by using point-counting planimetry to determine the area of the profiles of the myocardium). The volume of the myocardium (variable Y) was correlated to embryonic crown-rump length (variable X in millimeters) and age (in days). The bivariate allometric equation was used as Y = aXb. The scatterplot was discontinuous, presenting two trends during the postsomitic period. The first part was composed of embryos staged from stages 15 to 20, and the second part by embryos staged from stages 21 to 23. The breakpoint between these different trends was found at the level of stage 20 (embryo of 22 mm in crown-rump length and age nearly of 52 days). From stages 15 to 20, the growth rate of the myocardium was allometrically negative. On the other hand, from stages 21 to 23 this growth rate was moderately allometrically positive. These differences in growth of the myocardium were analyzed and, at least partially, might be due to the functional circulatory increase in the peripheral vascular bed in correlation to the cardiac hemodynamic demand required at the end of the embryonic period proper.     

Morphometric studies on the development of human thyroid gland in early fetal life.

Histological and morphometric studies were performed on 30 thyroid glands obtained from normal human fetuses. Their crown-rump length (CRL) ranged from 57 to 190 mm, corresponding to the gestational age of 10-20 weeks. The weight of the thyroid gland increased proportionally in relation to CRL, foot length and fetus weight. The first follicles containing PAS-positive colloid were observed in the peripheral part of the thyroid gland of 57 mm CRL fetus. The number of follicles per 1 mm2 of thyroid surface section increased up to 85 mm CRL and thereafter gradually declined for the end of studied period of fetal life. The volumes (in mm3) of thyroid epithelium, colloid and stroma, beginning from 85 mm increased proportionally to the CRL while the height of epithelial cells did not change. The epithelium/colloid ratio decreased notably to 165 mm CRL and thereafter remained constant. Results of the present study suggest that the thyroid gland of human fetus approaches structural maturity in 17.5 week of gestation.     

Prenatal development of the human nucleus ambiguus during the embryonic and early fetal periods

The ontogenetic development of the nucleus ambiguus was studied in a series of human embryos and fetuses ranging from 3 to 12.5 weeks of menstrual age (4 to 66 mm crown-rump length). They were prepared by Nissl and silver methods. Nucleus ambiguus neuroblasts, whose neurites extend towards and into the IXth and rostral Xth nerve roots, appear in the medial motor column of 4-6-week-old embryos (4.25-11 mm). These cells then migrate laterally (6.5 weeks, 14 mm) to a position near the dorsal motor nucleus of X. At 7 weeks (15 mm), nucleus ambiguus cells begin their migration, which progresses rostrocaudally, into their definitive ventrolateral position. The basic pattern of organization of the nucleus is established in its rostral region at 8 weeks (22.2-24 mm) and extends into its caudal region by 9 weeks (32 mm), when its nearly adult organization is evident. Cells having the characteristics of mature neurons first appear rostrally in the nucleus during the 8.5-9-week period (24.5-32 mm), gradually increase in number, and constitute the entire nucleus at 12.5 weeks (65.5 mm). Definitive neuronal subgroups first appear at 10 weeks (37.5 mm) in the large rostral nuclear region. These features suggest that the human nucleus ambiguus develops along a rostrocaudal temporospatial gradient. Evidence indicates that function of nucleus ambiguus neurons, manifested by fetal reflex swallowing, occurs after the cells migrate into their definitive position, establish the definitive nuclear pattern, and exhibit mature characteristics.     

The flower and blossom morphology of Asteraceae correlates with composition of their pollinators

The correlation between flower morphology and share of different insect groups visiting them was studied for 15 Asteraceae species. We measured length and width of corolla tube of 100 flowers of each plant species and determined proportions of main groups of anthophilous insects during all blooming period. According to corolla length species under study ranged more or less uniformly from 2.16 mm (Tripleurospermum inodorum) up to 21.06 mm (Cirsium heterophyllum). The correlation between share of long-tongued bees (mainly bumblebees) among all visitors of inflorescens and corolla length was positive (r = 0.737, P < 0.01) while for short-tongued flies (Syrphidae, Muscidae, Calliphoridae) it was negative (r = -0.869, P < 0.01). It is interesting, that the point of crossing of regression lines (12 mm) approximately coincides with change in inflorescences coloration. Plants with corolla length less than 10 mm have yellow or white inflorescences that are visited primarily by flies, while the plants with longer corolla have violet or dark blue inflorescences, by bumblebees. The dependence of proportion of short-tongued solitary bees (Andrenidae, Halictidae) on a corolla length was non-linear. It increased with increase in corolla length in an interval of 2.16-6.26 mm (r = 0.930, P < 0.1), but decreased for longer corollas (r = -0.680, P < 0.05). The correlation between corolla length and proportions of beetles and butterflies were insignificant.     

Histological development of the equine fetal adrenal gland.

The horse fetal adrenal gland was shown to begin to increase in weight from about the end of the 4th month of pregnancy when the fetus has a crown-rump length of about 20 cm. Growth then proceeds steadily to term but, in contrast to the adult horse, the medulla remains thicker than the cortex throughout fetal life. The cortex also becomes established around 20 cm crown-rump length and at the same time the glomerular and fascicular zones become distinguishable. In contrast the reticular zone is not differentiated until around 50 cm crown-rump length. In the fetal adrenal cortex, the fascicular zone is less prominent than in the adult horse although counts of cell nuclei in the cortical region indicate hypertrophy of the fascicular cells during the last third of gestation.     

Determination of early pregnancy and embryonic growth in goats by transrectal ultrasound scanning

Ultrasonography has been shown to be a useful tool for pregnancy diagnosis and the study of embryonic growth in mammals. The objectives of this study were 1) to evaluate the use of real-time B-mode ultrasonography for early pregnancy diagnosis in goats, 2) to define criteria for accurate diagnosis of pregnancy, and 3) to monitor the embryonic growth ultrasonically until Day 40 after mating. Estrus was synchronized in 16 cyclic Anglo-Nubian goats with a single injection of cloprostenol (125 micrograms, i.m.). Estrous females were randomly assigned into 2 groups: 1) goats mated by a vasectomized male (n = 5; MV group), and 2) goats mated by an intact male of proven fertility (n = 11; MF group). Transrectal ultrasonographic examinations with a 5 MHz linear array transducer were performed from Days 13 to 40 post mating. The evaluated parameters included the appearance of nonechogenic areas in the uterus, presence of embryo(s), crown-rump length of embryo and embryonic heart rate (beats/min). On Day 18, the mean (+/- SEM) diameter of nonechogenic areas was 1.5 +/- 0.3 mm in the MV group and 4.0 +/- 0.5 mm in the MF group (P < 0.01). In 36% of the pregnant does these areas were less than 3 mm. The mean (+/- SEM) day of the first detection by means of heartbeats of at least 1 embryo was 20.7 +/- 0.5 d (range, Days 19 to 23). From Days 19 to 38 of pregnancy, crown-rump length was best represented by a linear regression (Y = -2.23 + 0.13X; r2 = 0.94; P < 0.05). Crown-rump length on the day of the first detection of an embryo was 5.3 +/- 0.3 mm, reaching 34.2 +/- 0.6 mm on Day 40. Mean (+/- SEM) heartbeat rate was 168.3 +/- 2.8 beats/min on Day 21, decreasing to 158.3 +/- 2.0 beats/min on Day 40. Detection of the caprine embryo by ultrasonography and confirmation of its viability by heartbeats was shown to be a reliable method for early pregnancy diagnosis in Anglo-Nubian goats. Ultrasonic measurement of crown-rump length was useful in predicting the age of the embryo.     

Serum insulin-like growth factor-I, insulin-like growth factor binding protein-3, and the pubertal growth spurt in the female rhesus monkey

While there is good evidence suggesting IGF-I links to pubertal development and crown-rump length growth among rhesus monkeys, linkages between IGF-I and other measures of morphological growth have not been established. In this study, the pubertal growth spurt in a number of morphological characteristics of female rhesus monkeys is related to serum endocrine status of insulin-like growth factor-I (IGF-I) and its binding protein, insulin-like growth factor binding protein-3 (IGFBP-3), to test the hypothesis that elevations in IGF-I and IGFBP-3 coincide with the time of greatest growth rate of different morphological characteristics. A longitudinal study of pubertal growth among four female rhesus monkeys was carried out across a 3-year period. Morphometric measurements included weight, crown-rump length, foot-length, and skinfolds at five sites (biceps, triceps, abdominal, subscapular, and suprailiac). These measures were taken as being representative of total mass, skeletal growth of the trunk and head, limb length, and body fatness, respectively. Measurements were carried out as closely as possible to 3-monthly, with interpolations being performed to standardise the data to exactly 3-monthly intervals for all individuals. Blood samples were taken at time of morphometry. Elevations in serum IGF-I and IGFBP-3 took place in a manner similar to that of humans, and across the period associated with onset of puberty. Mean 3-monthly gain in crown-rump length and foot length showed significant peaks across the measurement period, while mean 3-monthly gains in weight and sum of five skinfolds did not. Greatest foot length gain occurred on average between 3-3.5 years of age, while crown-rump length gain was greatest between 3.75-4 years of age. Periods of greatest gain in crown-rump length and foot length took place across the period of elevated serum IGF-I levels, which was between 3-4.5 years of age. Significant elevations in IGF-I and IGFBP-3 were not coincident with greatest gains in foot length or crown-rump length. Thus the hypothesis does not hold true for the two measures showing significant peaks in 3-monthly gain across the measurement period. The nature of the endocrine impact on macaque morphology remains unclear, although this may be fundamental to the understanding of the variation in the pubertal growth spurt and its influence on morphology at maturity both within and across primate species.     

Contribution of the aortopulmonary septum to the muscular outlet septum in the human heart

The development of the outlet septum has been studied microscopically in 14 human embryos, ranging from 9 to 28 mm crown-rump length. Three tissue components are involved in the septation process: condensed mesenchyme of extracardiac origin, myocardium and endocardial cushion tissue. At the stage of 9 1/2 mm the condensed mesenchyme, which is embedded in the endocardial cushion tissue, is in contact with the myocardium at two sites. Graphic reconstructions of a 16 mm embryo show that at these sites of contact the myocardium is "drawn inwards" to form two bulges interconnected by the condensed mesenchyme. With further development the two myocardial bulges become the main mass of what then can be called the outlet septum. Thus the sites of contact between condensed mesenchyme and myocardium can be considered to represent the sites of attachment of the muscular outlet septum. This has important implications for the elucidation of the development of outlet malformations.     

The natural history of gastroschisis during fetal life: development of the fibrous coating on the bowel loops

Patients with gastroschisis have a paraumbilical defect of the anterior abdominal wall through which bowel loops protrude. These bowel loops are edematous and covered by a fibrous coating. The moment of occurrence of gastroschisis as well as the development of the fibrous coating are unknown. This prompted an investigation of 26 human embryos and fetuses with gastroschisis at various developmental stages (crown-rump length 25-240 mm) and two stillborn fetuses (gestational age 30 weeks) with gastroschisis, as well as resected material from ten newborns (gestational age 33-40 weeks) operated for gastroschisis. Progressive changes of the serosa were only noted after the 30th week of gestation and consisted of an amniotic fluid peritonitis and progressive fibrosis. The changes are in agreement with experimental data and correlate with changes in the composition of amniotic fluid. The findings prove that gastroschisis is a very early occurrence, while the fibrous coating is a late development.     

Diversity of cell lengths in terminal portions of roots: implications to cell proliferation

Terminal meristems are responsible for all primary growth of roots. It has been asserted that all cells of root meristems are actively dividing (no cells cycle slowly or arrest in the cycle) and stem cell populations expand exponentially. Because cells do not slide relative to each other in roots, relative cell lengths may be used to determine relative cell cycle durations and/or proportions of cells actively dividing in root tissues. If all cells are cycling, no interphase cells should be longer than critical length (length of longest mitotic cell in the meristem) and cells should exhibit an exponential cell-age distribution. Lengths of all cells were obtained radially across entire median longitudinal root sections at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mm from the founder cell/root cap boundary for five plant species to estimate percentages of cells longer than critical length. For example, up to 15 and 90% of all interphase cells were longer than critical length in 0.5 and 2.0 mm tissues, respectively, indicating that slow-cycling and/or non-proliferative cells are present in such tissues. In order to determine if the distribution of cell lengths in 0.5 mm segments approximated an exponential cell-age distribution, lengths of interphase cells less than critical length were determined. Such interphase cells were placed into ten groups according to cell length and percentages of cells in each group were compared with percentages of cells in groups calculated from an exponential cell-age distribution. Percentages of cells were significantly different from predicted percentages of between 6 and 9 out of ten groups - cell lengths were not distributed exponentially. Because there are significant numbers of interphase cells longer than critical length and since lengths of interphase cells shorter than critical length do not resemble an exponential cell-age distribution, it must be concluded that not all cells in root segments from 0.5 to 3.0 mm root segments are actively dividing. Heretofore, no databases of cell lengths have been used to test these assertions.     

西南大西洋阿根廷滑柔鱼生物学年间比较

将2007年2—5月、2008年3—5月、2010年1—3月我国鱿钓船在西南大西洋公海海域采集的阿根廷滑柔鱼样本,比较其不同年间的生物学特性。结果表明,渔获物雌雄比为1.14—1.50:1;3a雌性个体的胴长(体重)分别为188—346mm(110—856g)、200—364mm(145—950g)、124—276mm(72—425g),雄性个体的胴长(体重)为178—298mm(102—703g)、193—314mm(145—680g)、104—335mm(70—374g)。2010年渔获个体明显比2007和2008年小。各年间及雌、雄个体间的体重与胴长关系均存在差异(P<0.001),渔获物中年间性成熟组成差异明显,此外各年3月份渔获个体也存在显著差异。雌、雄个体的胴长平均生长率分别为0.53—1.07 mm/d、0.47—0.68 mm/d,相对生长率分别为0.24—0.41%d-1、0.23—0.33%d-1;雌、雄个体的体重平均生长率在1.70—5.25 g/d、1.64—4.59 g/d,相对生长率分别为0.92—1.37%d-1、0.86—1.40%d-1。渔汛期间,胴长、体重与时间的关系均符合指数生长曲线,但生长指数年间差异明显。综合分析认为:2007年渔获物基本上为南巴塔哥尼亚种群;2008年以南巴塔哥尼亚种群为主,但也有少量较小个体的夏季产卵种群;2010年则以夏季产卵种群为主,并有少量的南巴塔哥尼亚种群。     

Knemometry in the assessment of short-term linear growth in a population of healthy school children.

Short-term lower leg length increments were monitored with weekly knemometry measurements during 3 months in 27 healthy school children aged 8-12 years. One year after the first visit the children were measured once again. The mean short term velocity of lower leg growth was 0.40 mm/week (SD 0.12 mm/week). The mean short-term and annual ratios between height velocity and lower leg growth velocity were identical (2.8). The relative variation between two observers was 0.08%. Knemometry is a suitable method for monitoring short-term linear growth in populations of children. Two trained observers may substitute for each other in group studies.     

The differential contribution of premaxillary,maxillary, and palatine dimensions to sexual dimorphism in the adult olive baboon (Papio cynocephalus anubis)

Measurements of the palatal components: premaxillary, maxillary, and palatine length are made on the adult skulls of 19 male and 21 femalePapio cynocephalus anubis. The relative contributions of each of these components to overall palatal length are compared between the sexes. It is found that the proportions are the same for the two sexes and concluded that sexual dimorphism observed in the adult is not the result of differential growth of one component.