17 Chronobiological Serial Section Analysis with a Pocket Calculator

AbstractThis study examined the effects of metabotropic glutamate receptor 6 (mGluR6) deficiency on ribbon synapse formation in rod spherules and cone pedicles using serial-section electron microscopy. In a wild-type (WT) mouse, only 3% of spherules had one invaginating bipolar dendrite (1B-type) and 97% of spherules were 2B-type. In contrast, in an mGluR6-knockout (KO) mouse, 29% of spherules were 1B-type and 71% of spherules were 2B-type. Spherules without bipolar invagination were not observed in either genotype. The single invaginating dendrites in 1B-type spherules were larger and the surface areas of synaptic ribbons were 23% smaller in the mGluR6-KO mouse than in the WT mouse. In cones, the number of invaginating bipolar dendrites decreased from 12 in the WT mouse to 9.5 in the mGluR6-KO mouse. This decrease correlated with a decrease in the number of cone synaptic ribbons from 10 in the WT mouse to 8 in the mGluR6-KO mouse. The mGluR6-KO phenotype showed negative effects on ribbon synapse formation. This negativity was similar to those in mGluR6-nob4, Gβ3-KO, Gβ5-KO, and RGS-7:RGS-11 double-KO mice, but the detailed manners and degrees of alterations appeared to vary depending on different missing components. Two published morphological assessments of the RGS-7:RGS-11 double-KO phenotype reported conflicting data; therefore, we tested the statistical techniques used in the two analyses. One statistical evaluation measure was effective in identifying a significant difference in structure between the mutant and WT phenotypes, whereas the other measure was ineffective. Conventional random section analysis using the effective measure provided sufficient data for a statistical test of the occurrence of structural changes. However, serial section analysis was required to determine the absolute numbers of ribbons and invaginating dendrites and to estimate structural parameters such as ribbon surface area.

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3-D Serial Section Analysis of Polycrystals

Microscopy and Microanalysis ◽

10.1017/s1431927604883521 ◽

2004 ◽

Vol 10 (S02) ◽

pp. 732-733

Author(s):

James H Steele

Keyword(s):

Serial Section ◽

Section Analysis

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

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Karyotypic analysis of Membranosorus heterantherae (Plasmodiophoromycetes)

Canadian Journal of Botany ◽

10.1139/b89-159 ◽

1989 ◽

Vol 67 (4) ◽

pp. 1219-1220 ◽

Cited By ~ 3

Author(s):

James P. Braselton

Keyword(s):

Chromosome Number ◽

Serial Section ◽

Karyotypic Analysis ◽

Haploid Chromosome Number ◽

Synaptonemal Complexes ◽

Section Analysis

Synaptonemal complexes in nuclei of transitional plasmodia of Membranosorus heterantherae were counted through serial section analysis. The haploid chromosome number was determined to be 35, which distinguishes Membranosorus from other plasmodiophorid genera.

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Routing of internalized ricin and ricin conjugates to the Golgi complex.

The Journal of Cell Biology ◽

10.1083/jcb.102.1.37 ◽

1986 ◽

Vol 102 (1) ◽

pp. 37-47 ◽

Cited By ~ 154

Author(s):

B van Deurs ◽

T I Tønnessen ◽

O W Petersen ◽

K Sandvig ◽

S Olsnes

Keyword(s):

Horseradish Peroxidase ◽

Golgi Complex ◽

Serial Section ◽

Colloidal Gold ◽

Vero Cells ◽

Coated Vesicle ◽

Electron Microscopical ◽

Endosomal System ◽

Section Analysis ◽

Mcf 7

Receptor-mediated endocytosis and intracellular routing of native ricin, and of ricin conjugated to colloidal gold (Ri-Au) and to horseradish peroxidase (Ri-HRP), have been studied in cultured MCF-7 and Vero cells by electron microscopical techniques including serial section analysis. Both native ricin, as demonstrated by immunoperoxidase cytochemistry, and the ricin conjugates were internalized via a common coated pit-coated vesicle pathway to reach vacuolar and tubulo-vesicular portions of the endosomal system. In addition, native ricin and a purified monovalent fraction of Ri-HRP reached distinct Golgi cisterns, whereas Ri-Au and polyvalent Ri-HRP did not. The results delineate intracellular routing of native ricin and compare it with the routing of different ricin conjugates. Moreover, our study shows that conjugates of a particular ligand (ricin) and various probes (e.g., gold and peroxidase), may be handled differently by cells. Sorting apparently takes place in the endosomal system, allowing some but not other molecules to reach Golgi elements. This sorting seems to depend on the valency of the ricin conjugate.

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