Concept explainers
Enhanced Spatial Learning in Mice With an Autism Mutation Autism is a neurobiological disorder with symptoms that include impaired social interactions and stereotyped patterns of behavior. Around 10 percent of autistic people have an extraordinary skill or talent such as greatly enhanced memory.
Mutations in neuroligin 3, an adhesion protein that connects brain cells to one another, have been associated with autism. One mutation changes amino acid 451 from arginine to cysteine. In 2007, Katsuhiko Tabuchi and his colleagues genetically modified mice to carry the same arginine-to-cysteine substitution in their neuroligin 3. Mice with the mutation had impaired social behavior.
To test spatial learning ability, the mice were placed in a water maze: a deep pool of warm water in which a platform is submerged a few millimeters below the surface. The platform is not visible to swimming mice. Mice do not particularly enjoy swimming, so they locate a hidden platform as fast as they can. When tested again, they can remember its location by checking visual cues around the edge of the pool. How quickly they remember the platform’s location is a measure of spatial learning ability (FIGURE 15.18).
FIGURE 15.18 spatial learning ability in mica mutation in neuroligin 3 (R451C), compared with unmodified (wild-type) mica.
2. Did the modified or the unmodified mice learn the location of the platform faster in the first test?
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Biology: The Unity and Diversity of Life (MindTap Course List)
- Two types of mutations discussed in this chapter are (1) nucleotide changes and (2) unstable genome regions that undergo dynamic changes. Describe each type of mutation.arrow_forwardEnhanced Spatial Learning Ability in Mice Engineered to Carry an Autism Mutation Autism is a neurobiological disorder with symptoms that include impaired social interactions and repetitive, stereotyped patterns of behavior. Around 10 percent of autistic people also have an extraordinary skill or talent such as greatly enhanced memory. Mutations in the gene for neuroligin 3, an adhesion protein that connects brain cells, have been associated with autism. One of these mutations is called R451C because the altered gene encodes a protein with an amino acid substitution: a cysteine (C) instead of an arginine (R) in position 451. In 2007, Katsuhiko Tabuchi and his colleagues introduced the R451C mutation into the neuroligin 3 gene of mice. The researchers discovered that the genetically modified mice had impaired social behavior and superior spatial learning ability. Spatial learning in mice is tested with a water maze, which consists of a small platform submerged a bit below the surface or a pool of water so it is invisible to a swimming mouse. Mice do not particularly enjoy swimming, so they try to locate the hidden platform as quickly as they can. When tested again later, they remember the platforms location by checking visual cues around the edge or the pool. How quickly they remember is a measure of their spatial learning ability. FIGURE 15.14 shows some or Tabuchis result. FIGURE 15.14 Spatial learning ability in mice. Mice with a mutation in neuroligin 3 (R451C) were tested for learning performance: as compared with unmodified (wild-type) mice. Did the modified or the unmodified mice learn the location of the platform faster in the first test?arrow_forwardThe following is a portion of a protein: met-trp-tyr-arg-gly-pro-thr-Various mutant forms of this protein have been recovered. Using the normal and mutant sequences, determine the DNA and mRNA sequences that code for this portion of the protein, and explain each of the mutations. a. met-trp- b. met-cys-ile-val-val-leu-gln- c. met-trp-tyr-arg-ser-pro-thr- d. met-trp-tyr-arg-gly-ala-val-ile-ser-pro-thr-arrow_forward
- THE MOLECULAR GENETICS OF CYSTIC FIBROSIS and of The following is the base sequence of DNA that codes for amino acids 506-510 of the protein that regulates the chlorine channels in the cell membrane. This protein contains a total of 1476 amino acids so this is a small part of the entire gene. DNA Template Strand: 3'TAGTAGAAACCACAA5' 1. What is the minimum number of DNA nucleotides in this whole gene? 2. What is the sequence of bases on the strand of DNA that is complementary to the template strand? 3. What mRNA will be formed from the template strand of DNA? 4. What amino acids will this mRNA code for? 5. If the 6th, 7th and 8th bases in the template strand of the DNA are removed, rewrite the new template strand below. 6. When the template strand of the DNA is changed, this is referred to as a mutation. What kind of mutation is this? 65arrow_forwardYou suspect a protein that is being expressed has been affected by a mutation. When you examine the fully functional protein you find curiously that it still has retained all of its overall function. A friend of yours doing research with you assures you when examining the genetic data a new mutation does in fact exist in this protein. What is the most likely type of mutation that occurred based on this information? Group of answer choices frameshift mutation silent mutation nonsense mutationarrow_forwardBased on standard MS- LS3-1: Fish in a cave system in Mexico is missing its eyes, has thin, translucent skin, and is relatively small (7-10 cm in length). Can you describe by model why structural changes to genes (mutations) on chromosomes may affect proteins and may result in beneficial effects to the structure and function of the fish? Can you answer in the following format? 1- Structure How Structure and Function is Affected by Mutations in Blind Fish Eyes Scales Taste Cells Lateral Line 2- Model to explain what causes these changes: Change: ______________ Adapting an Organism to the Dark Cause: ________________ Stop the Growth of Eyes Effect: ___________________ Fish with Heightened Other Senses References: Video: Rare Blind Cave Fish in Mexican Cave System https://www.youtube.com/watch?v=MWdtGuDd8z0 Fact Sheet: Blind Cave Fish https://www.denverzoo.org/animals/blind-cave-fish Information: Mexican Tetra…arrow_forward
- What type of mutation is this? 1. Which type of mutation is responsible for new varia tions of a trait? Which type of mutation does not result in an abnormal amino acid sequece? Which type of mutation stops the translation of an mRNA molecule? 2. Sickle Cell Anemia Sickle cell anemia is the result of a type of mutation in the gene that codes for part of the hemoglobin molecule Hemoglobin carries oxygen in your red bloods cells. The mutation causes these red blood cells to become stife sickle-shaped when they release their oxygen. The sickled cells tend to get stuck in blood vessels, causing poin ond increased risk of stroke, blindness, damage to the heart & lungs, and other conditions. Analyze the DNA strands below to determine what amino acid is changed AND what type of mutation occurred Normal hemoglobin DNA A G TC Normal hemoglobin mRNA val• Hisolelo thr•proo Gll Normal hemoglobin AA sequence CA cGT AG A CTGAGG AC AC Sickle cell hemoglobin DNA Sickle cell hemoglobin mRNA Sickle cell…arrow_forwardIn humans, sickle-cell anemia and hemophilia represent which type of mutations? Loss of function mutation Gain of function mutation Behavioral Mutation Biochemical mutationarrow_forwardGood afternoon, Guidance with this question would be most appriciated. Thank you for your time. Polypeptide sequences are formed from 20 amino acids. What is the probability that a single point mutation in a gene will result in a different polypeptide sequence?arrow_forward
- Match the relationships to the corresponding concepts. Expanding nucleotide repeat..... Somatic mutation Base substitution Transition Missence mutation Nuetral mutation Mutation Germline mutation Transversion Silent mutation Indels Frameshift mutation Nonsense mutation Inherited change in DNA sequence Loss of function mutation Gain of function mutation Insertions Deletions Reading frame Answer Bank involving the number of repeat sequences often lead to if removes function alteration of single nucleotides are often alter the alters sense codon to stop codon substitution of unlike base alters the amino acid in protein insertions and deletions of sequences are based on type of tissue, can be does not alter function substitution of like base defined as does not alter amino acid in protein if gains functionarrow_forwardSusceptibility to developing prion diseases arises from a mutation that changes aspartic acid (Asp) to asparagine (Asn). Which nucleotide base changes could make this happen?arrow_forwardWhich statement is FALSE? Group of answer choices Histones are very conserved at the primary sequence level in eukaryotes. Histones H2A, H2B, and H1 all contain the histone fold domain (HFD). CENPA is most closely related to histone H3. The amino terminal tail of histone H3 is the location of most of its covalent modifications. Amino terminal ends of core histones are involved in internucleosome interactions.arrow_forward
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