scholarly journals Pig zona pellucida 2 (pZP2) protein does not participate in zona pellucida formation in transgenic mice

Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Akiko Hasegawa ◽  
Nozomi Kanazawa ◽  
Hideaki Sawai ◽  
Shinji Komori ◽  
Koji Koyama

The zona pellucida, an extracellular matrix surrounding mammalian oocytes, is composed of three or four glycoproteins. It is well known that the zona pellucida plays several critical roles during fertilization, but there is little knowledge about its formation. The purpose of this study is to examine whether a pig zona pellucida glycoprotein 2 (pZP2) would assemble with mouse zona pellucida. A transgene construct was prepared by placing a minigene encoding pZP2 downstream from the promoter of mouse ZP2. The result showed that the transgenic protein was synthesized in growing oocytes but not incorporated into the zona pellucida. Furthermore, the pZP2 transgene did not rescue the phenotype in ZP2-knockout zona-deficient mice. These results indicate that pZP2 does not participate in mouse zona pellucida formation and the zona pellucida is constituted from its component proteins in a molecular species-specific manner between mice and pigs.

2019 ◽  
Vol 111 (4) ◽  
pp. 794-805 ◽  
Author(s):  
Julie A. MacDonald ◽  
Yasushi Takai ◽  
Osamu Ishihara ◽  
Hiroyuki Seki ◽  
Dori C. Woods ◽  
...  

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Raja Nadif ◽  
Michael Emerson ◽  
Ulrike Mayer ◽  
Ludwig Neyses ◽  
Elizabeth Cartwright

Effective propagation of the electrical impulse throughout the myocardium is highly dependent on cell-to-cell and cell-to-extracellular matrix interactions. Increasing evidence indicates that dysregulation of cellular adhesion is a critical determinant in the genesis of arrhythmia. Null mutations in the integrin α7 gene, an essential mediator of cellular adhesion in cardiac and skeletal muscles, have been linked to myopathy in humans, however, the in vivo role of the integrin α7 subunit in the heart is undefined. The mouse model of integrin α7 deletion dies prematurely at one year of age. We therefore analysed the cardiac phenotype in integrin α7 deficient mice (α7 −/− ) to determine whether their premature death was associated with altered cardiac conduction. One year old integrin α7 −/− mice exhibited altered cardiac conduction characterised by spontaneous atrial fibrillation and prolonged QTc duration (α7 −/− : 25.7±0.74ms, α7 +/+ : 19.5±0.61ms; n=6; p<0.001, QTc=QT/(RR/100) 1/2 ). The abnormal cardiac conduction was associated with downregulation of connexin43. However, no significant changes were observed in the expression of ion chanels that have been linked to long QT syndrome or atrial fibrillation (kv1.1, kv1.5, kcne1, kcnq1, erg1, Cav1.2 and Cav1.3). In addition, α7 −/− mice displayed increased susceptibility to drug-induced arrhythmias: treatment with ouabain (2mg/kg BW) in combination with isoprenaline (2.5mg/kg BW) induced atrial fibrillation and ventricular tachycardia and eventually death in 6 month-old integrin α7 −/− mice, but not in α7 +/+ mice. Interestingly, α7 −/− also displayed concentric ventricular hypertrophy with increased septal wall thickness and reduced left ventricular end-diastolic diameter starting from 6 months of age. These structural changes were accompanied by an increase in myocyte size and increased ERK1/2 phosphorylation. In conclusion, deletion of the integrin α7 gene in mice leads to ventricular hypertrophy and to abnormal cardiac conduction. The integrin α7 deficient mice have a marked propensity to lethal arrhythmias through alterations in gap junctions but not ion channels. The integrin α7 knockout model provides new insight into the link between the extracellular matrix and cardiac conduction.


Development ◽  
1990 ◽  
Vol 108 (1) ◽  
pp. 1-17 ◽  
Author(s):  
P.M. Wassarman

Complementary molecules on the surface of eggs and sperm are responsible for species-specific interactions between gametes during fertilization in both plants and animals. In this essay, several aspects of current research on the mouse egg receptor for sperm, a zona pellucida glycoprotein called ZP3, are addressed. These include the structure, synthesis, and functions of the sperm receptor during oogenesis and fertilization in mice. Several conclusions are drawn from available information. These include (I) ZP3 is a member of a unique class of glycoproteins found exclusively in the extracellular coat (zona pellucida) of mammalian eggs. (II) ZP3 gene expression is an example of oocyte-specific and, therefore, sex-specific gene expression during mammalian development. (III) ZP3 is a structural glycoprotein involved in assembly of the egg extracellular coat during mammalian oogenesis. (IV) ZP3 is a sperm receptor involved in carbohydrate-mediated gamete recognition and adhesion during mammalian fertilization. (V) ZP3 is an inducer of sperm exocytosis (acrosome reaction) during mammalian fertilization. (VI) ZP3 participates in the secondary block to polyspermy following fertilization in mammals. (VII) The extracellular coat of other mammalian eggs contains a glycoprotein that is functionally analogous to mouse ZP3. The unique nature, highly restricted expression, and multiple roles of ZP3 during mammalian development make this glycoprotein a particularly attractive subject for investigation at both the cellular and molecular levels.


2004 ◽  
Vol 18 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Thu H. Le ◽  
Michael I. Oliverio ◽  
Hyung-Suk Kim ◽  
Harmony Salzler ◽  
Rajesh C. Dash ◽  
...  

To understand the physiological role of angiotensin type 1 (AT1) receptors in the proximal tubule of the kidney, we generated a transgenic mouse line in which the major murine AT1 receptor isoform, AT1A, was expressed under the control of the P1 portion of the γ-glutamyl transpeptidase (γGT) promoter. In transgenic mice, this promoter has been shown to confer cell-specific expression in epithelial cells of the renal proximal tubule. To avoid random integration of multiple copies of the transgene, we used gene targeting to produce mice with a single-copy transgene insertion at the hypoxanthine phosphoribosyl transferase ( Hprt) locus on the X chromosome. The physiological effects of the γGT-AT1A transgene were examined on a wild-type background and in mice with targeted disruption of one or both of the murine AT1 receptor genes ( Agtr1a and Agtr1b). On all three backgrounds, γGT-AT1A transgenic mice were healthy and viable. On the wild-type background, the presence of the transgene did not affect development, blood pressure, or kidney structure. Despite relatively low levels of expression in the proximal tubule, the transgene blunted the increase in renin expression typically seen in AT1-deficient mice and partially rescued the kidney phenotype associated with Agtr1a−/− Agtr1b−/− mice, significantly reducing cortical cyst formation by more than threefold. However, these low levels of cell-specific expression of AT1 receptors in the renal proximal tubule did not increase the low blood pressures or abolish sodium sensitivity, which are characteristic of AT1 receptor-deficient mice. Although our studies do not clearly identify a role for AT1 receptors in the proximal tubules of the kidney in blood pressure homeostasis, they support a major role for these receptors in modulating renin expression and in maintaining structural integrity of the renal cortex.


1999 ◽  
Vol 67 (6) ◽  
pp. 3087-3095 ◽  
Author(s):  
Peter J. Murray ◽  
Richard A. Young

ABSTRACT Macrophage effector functions are essential for clearing mycobacterial infections. Interleukin 10 (IL-10) negatively regulates macrophages and could be a factor inhibiting effective antimycobacterial immunity. We previously showed that transgenic mice which produce excess IL-10 from T cells are susceptible to infection, even though these mice continue to produce gamma interferon (IFN-γ) at levels similar to those in controls. Here, we extend our genetic analysis of the functions of IL-10 in antimycobacterial immunity by testing the hypothesis that IL-10-deficient (IL-10−/−) mice should be more resistant to mycobacteria than control mice.Mycobacterium bovis bacillus Calmette-Guérin-infected IL-10−/− mice had significantly lower bacterial burdens than control mice early in the infection. Contrary to expectations, however, IL-10−/− mice did not have increased levels of IFN-γ, either from T cells or in the plasma, suggesting that other mechanisms are responsible for the increased resistance. However, macrophages from IL-10−/− mice produced increased levels of inflammatory cytokines, including IFN-γ, as well as nitric oxide and prostaglandins, which could account for increased antimycobacterial immunity. Our genetic analysis revealed that IL-10 is an inhibitor of early mycobacterial clearance. The data also suggest that IL-10 negatively regulates numerous macrophage functions as well as playing a role in down-regulating the general inflammatory response, especially in conditions where an infection must be controlled through macrophage activity.


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