Relationships of basal metabolic rate, relative testis size and cycle length of spermatogenesis in shrews (Mammalia, Soricidae)

2008 ◽  
Vol 20 (3) ◽  
pp. 431 ◽  
Author(s):  
Roumen Parapanov ◽  
Sébastien Nusslé ◽  
Jacques Hausser ◽  
Peter Vogel
Keyword(s):  
Metabolic Rate ◽  
Mating System ◽  
Sperm Competition ◽  
Basal Metabolic Rate ◽  
Cycle Length ◽  
System Level ◽  
Testis Size ◽  
Suncus Murinus ◽  
Sperm Production ◽  
Sorex Minutus

The aim of the present study was to determinate the cycle length of spermatogenesis in three species of shrew, Suncus murinus, Sorex coronatus and Sorex minutus, and to assess the relative influence of variation in basal metabolic rate (BMR) and mating system (level of sperm competition) on the observed rate of spermatogenesis, including data of shrew species studied before (Sorex araneus, Crocidura russula and Neomys fodiens). The dynamics of sperm production were determined by tracing 5-bromodeoxyuridine in the DNA of germ cells. As a continuous scaling of mating systems is not evident, the level of sperm competition was evaluated by the significantly correlated relative testis size (RTS). The cycle durations estimated by linear regression were 14.3 days (RTS 0.3%) in Suncus murinus, 9.0 days (RTS 0.5%) in Sorex coronatus and 8.5 days (RTS 2.8%) in Sorex minutus. In regression and multiple regression analyses including all six studied species of shrew, cycle length was significantly correlated with BMR (r2 = 0.73) and RTS (r2 = 0.77). Sperm competition as an ultimate factor obviously leads to a reduction in the time of spermatogenesis in order to increase sperm production. BMR may act in the same way, independently or as a proximate factor, revealed by the covariation, but other factors (related to testes size and thus to mating system) may also be involved.

scholarly journals Sperm competition and sperm length influence the rate of mammalian spermatogenesis

2009 ◽  
Vol 6 (2) ◽  
pp. 219-221 ◽  
Author(s):  
Steven A. Ramm ◽  
Paula Stockley
Keyword(s):  
Sperm Competition ◽  
Negative Relationship ◽  
Interspecific Variation ◽  
Sperm Length ◽  
Testis Size ◽  
Sperm Production ◽  
Selection For ◽  
High Level ◽  
Sperm Size ◽  
Numerical Advantage

Sperm competition typically favours an increased investment in testes, because larger testes can produce more sperm to provide a numerical advantage in competition with rival ejaculates. However, interspecific variation in testis size cannot be equated directly with variation in sperm production rate—which is the trait ultimately selected under sperm competition—because there are also differences between species in the proportion of spermatogenic tissue contained within the testis and in the time it takes to produce each sperm. Focusing on the latter source of variation, we provide phylogenetically controlled evidence for mammals that species with relatively large testes (and hence a high level of sperm competition) have a shorter duration of the cycle of the seminiferous epithelium and consequently a faster rate of spermatogenesis, enabling males to produce more sperm per unit testis per unit time. Moreover, we identify an independent negative relationship between sperm length and the rate of spermatogenesis, such that spermatogenesis takes longer in species with longer sperm. We conclude that sperm competition selects for both larger testes and a faster rate of spermatogenesis to increase overall sperm production, and that an evolutionary trade-off between sperm size and numbers may be mediated via constraints on the rate of spermatogenesis imposed by selection for longer sperm.

Variation in basal metabolic rate and activity in relation to reproductive condition and photoperiod in white-footed mice (Peromyscus leucopus)

2012 ◽  
Vol 90 (5) ◽  
pp. 602-615 ◽  
Author(s):  
P.A. Kaseloo ◽  
M.G. Crowell ◽  
J.J. Jones ◽  
P.D. Heideman
Keyword(s):  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Energy Use ◽  
Peromyscus Leucopus ◽  
Photoperiodic Response ◽  
Life History Trait ◽  
Testis Size ◽  
Reproductive Suppression ◽  
Long Day ◽  
Significant Difference

A naturally variable life-history trait with underlying physiological variation is the photoperiodic response of many temperate-zone rodents, including white-footed mice (Peromyscus leucopus (Rafinesque, 1818)). Male P. leucopus were obtained from a short photoperiod responsive (R) line, artificially selected for reproductive suppression in short-day conditions (SD) and a nonresponsive (NR) line selected for reproductive maturity in SD. We tested for variation in metabolic rate between lines in SD and long-day conditions (LD). NR mice consumed 34% more food than R mice, without concomitant increase in body mass in SD. Basal metabolic rate (BMR) was found to be significantly greater in NR than R mice, and NR mice were found to engage in significantly more spontaneous (daily) locomotor activity. Energy-use estimates based on 24 h respirometry matched closely the level of intake reported for individual mice. The increased BMR and average daily metabolic rate in NR mice was correlated with testis size, but not with major central organs or digestibility. No significant difference in BMR or activity was found in mice from the same lines held in LD. Elevated intake in SD mice appears to be associated with differences in fertility and not other aspects of physiology in the respective lines.

Human sperm competition: testis size, sperm production and rates of extrapair copulations

2004 ◽  
Vol 68 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Leigh W. Simmons ◽  
Renée C. Firman ◽  
Gillian Rhodes ◽  
Marianne Peters
Keyword(s):  
Sperm Competition ◽  
Human Sperm ◽  
Testis Size ◽  
Sperm Production

scholarly journals Larval social cues influence testicular investment in an insect

2021 ◽  
Author(s):  
Junyan Liu ◽  
Xiong Z He ◽  
Xia-Lin Zheng ◽  
Yujing Zhang ◽  
Qiao Wang
Keyword(s):  
Body Weight ◽  
Sperm Competition ◽  
Growth And Development ◽  
Social Cues ◽  
Social Setting ◽  
Testis Size ◽  
Sperm Production ◽  
Competition Level ◽  
Fine Tune ◽  
Paternity Share

Abstract Socio-sexual environment can have critical impacts on reproduction and survival of animals. Consequently, they need to prepare themselves by allocating more resources to competitive traits that give them advantages in the particular social setting they have been perceiving. Evidence shows that a male usually raises his investment in sperm after he detects the current or future increase of sperm competition because relative sperm numbers can determine his paternity share. This leads to the wide use of testis size as an index of the sperm competition level, yet testis size does not always reflect sperm production. To date, it is not clear whether male animals fine-tune their resource allocation to sperm production and other traits as a response to social cues during their growth and development. Using a polygamous insect Ephestia kuehniella, we tested whether and how larval social environment affected sperm production, testis size, and body weight. We exposed the male larvae to different juvenile socio-sexual cues and measured these traits. We demonstrate that regardless of sex ratio, group-reared males produced more eupyrenes (fertile and nucleate sperm) but smaller testes than singly reared ones, and that body weight and apyrene (infertile and anucleate sperm) numbers remained the same across treatments. We conclude that the presence of larval social, but not sexual cues is responsible for the increase of eupyrene production and decrease of testis size. We suggest that male larvae increase investment in fertile sperm cells and reduce investment in other testicular tissues in the presence of conspecific juvenile cues.

Development of new predictive equations for basal metabolic rate in Iranian healthy adults: negligible effect of sex

2020 ◽  
pp. 1-10
Author(s):  
Bahareh Nikooyeh ◽  
Nastaran Shariatzadeh ◽  
Ali Kalayi ◽  
Maliheh Zahedirad ◽  
Tirang R. Neyestani
Keyword(s):  
Metabolic Rate ◽  
Thyroid Function ◽  
Basal Metabolic Rate ◽  
Age Groups ◽  
Thyroid Function Tests ◽  
Anthropometric Measures ◽  
Predictive Equations ◽  
Normal Thyroid Function ◽  
Asian People ◽  
Predictive Formulas

Abstract. Some studies have reported inaccuracy of predicting basal metabolic rate (BMR) by using common equations for Asian people. Thus, this study was undertaken to develop new predictive equations for the Iranian community and also to compare their accuracy with the commonly used formulas. Anthropometric measures and thyroid function were evaluated for 267 healthy subjects (18–60 y). Indirect calorimetry (InCal) was performed only for those participants with normal thyroid function tests (n = 252). Comparison of predicted RMR (both kcal/d and kcal.kg.wt−1.d−1) using current predictive formulas and measured RMR revealed that Harris-Benedict and FAO/WHO/UNU significantly over-estimated and Mifflin-St. Jeor significantly under-estimated RMR as compared to InCal measurements. In stepwise regression analysis for developing new equations, the highest r2 (=0.89) was from a model comprising sex, height and weight. However, further analyses revealed that unlike the subjects under 30 y, the association between age and the measured RMR in subjects 30 y and plus was negative (r = −0.241, p = 0.001). As a result, two separate equations were developed for these two age groups. Over 80 percent of variations were covered by the new equations. In conclusion, there were statistical significant under- and over-estimation of RMR using common predictive equations in our subjects. Using the new equations, the accuracy of the calculated RMR increased remarkably.

COMBINATION OF POTASSIUM PERCHLORATE AND PROPYLTHIOURACIL IN THE TREATMENT OF THYROTOXICOSIS

1968 ◽  
Vol 57 (4) ◽  
pp. 565-577 ◽  
Author(s):  
K. E. Røkke ◽  
J. H. Vogt
Keyword(s):  
Drug Therapy ◽  
Side Effects ◽  
Metabolic Rate ◽  
Total Cholesterol ◽  
Basal Metabolic Rate ◽  
Combined Therapy ◽  
Combined Treatment ◽  
Control Measures ◽  
Potassium Perchlorate ◽  
Plasma Total Cholesterol

ABSTRACT A report is given on 95 thyrotoxic patients treated with a combination of 400 mg propylthiouracil and 400 mg of potassium perchlorate. Perchlorate was stopped when a marked remission of symptoms was obtained, on an average after less than 7 weeks. Euthyroidism was found on an average after 7.2 weeks. The basal metabolic rate, PBI, plasma total cholesterol and weight showed a fairly rapid normalization. Thirteen of the 95 patients were given radio-iodine therapy shortly before drug therapy was started. The remaining 82 cases were grouped together with the 23 cases previously reported. Of the total of 105 cases, 96 became euthyroid on combined therapy. For the frequency of side-effects, the thirteen cases mentioned above were included, giving a total of 118 cases. Eight cases showed an increase in goitre size and 15 cases had other side-effects, of which three were granulocytopenia due to propylthiouracil. The possibility of a higher frequency of mainly minor side-effects on combined therapy has to be balanced against the seemingly rapid and reliable therapeutic effect. Combined treatment, perhaps with even smaller doses than reported here, can be recommended in selected cases of thyrotoxicosis where a shortening of the thyrotoxic state seems of importance, or possibly where difficulties due to iodine exposure may be anticipated, provided adequate control measures are taken.

Can night eating syndrome increase basal metabolic rate?

2017 ◽  
Author(s):  
Senay Topsakal ◽  
Guzin Fidan Yaylalı ◽  
Semin Melahat Fenkci
Keyword(s):  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Night Eating Syndrome ◽  
Night Eating

Metabolic Age, an Index Based on Basal Metabolic Rate, Can Predict Individuals That are High Risk of Developing Metabolic Syndrome

2021 ◽  
Author(s):  
Sarahi Vásquez-Alvarez ◽  
Sergio K. Bustamante-Villagomez ◽  
Gabriela Vazquez-Marroquin ◽  
Leonardo M. Porchia ◽  
Ricardo Pérez-Fuentes ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
High Risk ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Metabolic Age

scholarly journals The decoupled nature of basal metabolic rate and body temperature in endotherm evolution

Nature ◽  
2019 ◽  
Vol 572 (7771) ◽  
pp. 651-654 ◽  
Author(s):  
Jorge Avaria-Llautureo ◽  
Cristián E. Hernández ◽  
Enrique Rodríguez-Serrano ◽  
Chris Venditti
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate
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