# VISUAL SEARCH AND FILM READER ERROR IN RADIOLOGY

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 1987 · $196,135

## Abstract

The long-term goal of these studies is the elucidation of the
molecular mechanisms which underlie chromosome behavior and
transmission.  Specifically, the experiments are focused on two
aspects of chromosome biology in the fruit fly Drosophila
melanogaster, namely rDNA magnification and meiotic
chromosome segregation.  In each case the approach is based on :
1) the isolation of mutations and relevant chromosomal
aberrations necessary for genetic dissection; 2) genetic and,
where possible, molecular analysis of chromosome behavior; 3) the
physical isolation of genes defined by these mutations; and 4)
molecular analysis of the structure and expression of these genes.

The term rDNA magnification denotes at least two phenomena
which result in heritable and stable increases in X chromosomal
rDNA redundancy within the germline of rDNA deficient males.
We propsoe a series of genetic and molecular experiments aimed
at:  1) elucidating the molecular mechanisms of magnification
events; 2) identifying the genes or gene systems which carry out
these events; and 3) determining the mechanisms by which the
cell senses an rDNA deficiency and induces or allows the
magnification response.  These studies will provide valuable
information regarding the mechanism by which cells can stably
maintain or alter the redundancy of tandemly repeated genes and
some insight into the mechanisms by which the rDNA is expressed
and regulated.

The second series of experiments centers on a genetic and
molecular analysis of the distributive pairing system.  This system
ensures the regular segregation of nonexchange chromosomes
during meiosis I in Drosophila females.  Although a few mutants
specifically defective in the process have been previously
isolated, a much more extensive screen for mutations affecting
distributive pairing is proposed.  While the purpose of this mutant
hunt is to obtain additional alleles of existing loci, it is also hoped
that new loci will be identified.  Experiments are also proposed to
clone at least three genes specifically involved in distributive
pairing.  The immediate objective of these studies is a molecular
analysis of a family of genes which function specifically during
meiosis to facilitate chromosome segregation.  Over a longer
term these experiments will provide the necessary tools to
identify the proteins encoded by these genes and determine their
cellular and/or chromosomal location.  This information will be
essential for a molecular understanding of chromosome
segregation.

## Key facts

- **NIH application ID:** 3170734
- **Project number:** 2R01CA032870-07
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **SAM.gov UEI:** GM1XX56LEP58
- **Principal Investigator:** HAROLD L. KUNDEL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $196,135
- **Award type:** 2
- **Project period:** 1980-08-01 → 1992-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3170734

## Citation

> US National Institutes of Health, RePORTER application 3170734, VISUAL SEARCH AND FILM READER ERROR IN RADIOLOGY (2R01CA032870-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3170734. Licensed CC0.

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