Male hybrid sterility in the cattle–yak and other bovines: a review

Author(s):  
Niayale Robert ◽  
Yan Cui ◽  
Adzitey Fredrick

Abstract Hybridization is important for both animal breeders attempting to fix new phenotypic traits and researchers trying to unravel the mechanism of reproductive barriers in hybrid species and the process of speciation. In interspecies animal hybrids, gains made in terms of adaptation to environmental conditions and hybrid vigour may be offset by reduced fertility or sterility. Bovine hybrids exhibit remarkable hybrid vigour compared to their parents. However, the F1 male hybrid exhibits sterility whereas the female is fertile. This male-biased sterility is consistent with Haldane’s rule where heterogametic sex is preferentially rare, absent, or sterile in the progeny of two different species The obstacle of fixing favourable traits and passing them to subsequent generations due to the male sterility is a major setback in improving the reproductive potential of bovines through hybridization. Multi-perspective approaches such as molecular genetics, proteomics, transcriptomics, physiology and endocrinology have been used by several researchers over the past decade in an attempt to unravel the potential mechanisms underlying male hybrid sterility. However, the mechanism of sterility in the hybrid male is still not completely unravelled. This review seeks to provide an update of the mechanisms of the sterility in the cattle-yak and other bovines.

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1747-1771 ◽  
Author(s):  
Daniel A Barbash ◽  
John Roote ◽  
Michael Ashburner

Abstract The Drosophila melanogaster mutation Hmr rescues inviable hybrid sons from the cross of D. melanogaster females to males of its sibling species D. mauritiana, D. simulans, and D. sechellia. We have extended previous observations that hybrid daughters from this cross are poorly viable at high temperatures and have shown that this female lethality is suppressed by Hmr and the rescue mutations In(1)AB and D. simulans Lhr. Deficiencies defined here as Hmr− also suppressed lethality, demonstrating that reducing Hmr+ activity can rescue otherwise inviable hybrids. An Hmr+ duplication had the opposite effect of reducing the viability of female and sibling X-male hybrid progeny. Similar dose-dependent viability effects of Hmr were observed in the reciprocal cross of D. simulans females to D. melanogaster males. Finally, Lhr and Hmr+ were shown to have mutually antagonistic effects on hybrid viability. These data suggest a model where the interaction of sibling species Lhr+ and D. melanogaster Hmr+ causes lethality in both sexes of species hybrids and in both directions of crossing. Our results further suggest that a twofold difference in Hmr+ dosage accounts in part for the differential viability of male and female hybrid progeny, but also that additional, unidentified genes must be invoked to account for the invariant lethality of hybrid sons of D. melanogaster mothers. Implications of our findings for understanding Haldane's rule—the observation that hybrid breakdown is often specific to the heterogametic sex—are also discussed.


1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.


Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.


Author(s):  
John Hunsley ◽  
Eric J. Mash

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.


2021 ◽  
pp. 088506662199232
Author(s):  
Xiaojuan Zhang ◽  
Xin Li

Septic shock with multiple organ failure is a devastating situation in clinical settings. Through the past decades, much progress has been made in the management of sepsis and its underlying pathogenesis, but a highly effective therapeutic has not been developed. Recently, macromolecules such as histones have been targeted in the treatment of sepsis. Histones primarily function as chromosomal organizers to pack DNA and regulate its transcription through epigenetic mechanisms. However, a growing body of research has shown that histone family members can also exert cellular toxicity once they relocate from the nucleus into the extracellular space. Heparin, a commonly used anti-coagulant, has been shown to possess life-saving capabilities for septic patients, but the potential interplay between heparin and extracellular histones has not been investigated. In this review, we summarize the pathogenic roles of extracellular histones and the therapeutic roles of heparin in the development and management of sepsis and septic shock.


1939 ◽  
Vol 17 (2) ◽  
pp. 69-82 ◽  
Author(s):  
D. W. Fenwick

Numerous attempts have been made in the past to induce the eggs of Ascaris suum to hatch outside the body of the host. Extra-corporeal hatching has been observed under a variety of conditions by different workers. Kondo (1920, 1922), Asada (1921) and others record hatching in water, charcoal and sand cultures. Wharton (1915) states that hatching will occur in alkaline digestive juices, while Martin (1913) records a similar phenomenon in pancreatic fluid. Many different explanations have been offered to explain this hatching. Wharton suggested that the interaction of algae and sand might have some effect. Ohba (1923), who found that hatching would occur in 0·2% hydrochloric acid and 0·2% sodium carbonate believed that extra-corporeal hatching was limited to very old cultures of eggs. Many workers are of the opinion that some stimulus normally present in the digestive tract is necessary for hatching.


2015 ◽  
Vol 370 (1681) ◽  
pp. 20140267 ◽  
Author(s):  
Paul J. Ferraro ◽  
Merlin M. Hanauer

To develop effective protected area policies, scholars and practitioners must better understand the mechanisms through which protected areas affect social and environmental outcomes. With strong evidence about mechanisms, the key elements of success can be strengthened, and the key elements of failure can be eliminated or repaired. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. This essay assesses what mechanisms have been hypothesized, what empirical evidence exists for their relative contributions and what advances have been made in the past decade for estimating mechanism causal effects from non-experimental data. The essay concludes with a proposed agenda for building an evidence base about protected area mechanisms.


1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.


Author(s):  
Wei Chen ◽  
S.L. Yuen ◽  
R.H.Y. So

This paper summarizes the progress made in the quest to establish a Cybersickness Dose Value (CSDV). The Motion Sickness Dose Value (MSDV), reported in the British Standard BS6841, has been used to predict the severity of seasickness since 1987. In 1999, the authors of this paper proposed a CSDV formulation with a structure similar to that of the MSDV (So, 1999). Since then, several experiments and simulation studies have been conducted to modify and develop the proposed CSDV formula. In particular, progress has been made in (i) the methods to measure CSDV, (ii) the determination of a frequency weighting curve to equalize the non-linear relationship between the navigation velocity and levels of cybersickness, and (iii) the detailed formulation of CSDV. This paper summarizes the past progress and reports on the current effort in developing a CSDV.


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